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2016-04-08UPSTREAM: seccomp: always propagate NO_NEW_PRIVS on tsyncHEADmastermainJann Horn
Before this patch, a process with some permissive seccomp filter that was applied by root without NO_NEW_PRIVS was able to add more filters to itself without setting NO_NEW_PRIVS by setting the new filter from a throwaway thread with NO_NEW_PRIVS. Signed-off-by: Jann Horn <jann@thejh.net> Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Bug: 27892194 Patchset: seccomp (cherry picked from commit 103502a35cfce0710909da874f092cb44823ca03) Signed-off-by: Kees Cook <keescook@google.com> Change-Id: I5a7290daff95794a1d67e0e7f5659a7ca8bfe91c
2016-04-08BACKPORT: seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNOKees Cook
The value resulting from the SECCOMP_RET_DATA mask could exceed MAX_ERRNO when setting errno during a SECCOMP_RET_ERRNO filter action. This makes sure we have a reliable value being set, so that an invalid errno will not be ignored by userspace. Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Bug: 27892194 Patchset: seccomp (cherry picked from commit 580c57f1076872ebc2427f898b927944ce170f2d) Signed-off-by: Kees Cook <keescook@google.com> Change-Id: I30c2741f7064914b04b8a2765f1fd40f3a1cbd9e
2016-03-24FROMLIST: mm: mmap: Add new /proc tunable for mmap_base ASLR.dcashman
(cherry picked from commit https://lkml.org/lkml/2015/12/21/337) ASLR only uses as few as 8 bits to generate the random offset for the mmap base address on 32 bit architectures. This value was chosen to prevent a poorly chosen value from dividing the address space in such a way as to prevent large allocations. This may not be an issue on all platforms. Allow the specification of a minimum number of bits so that platforms desiring greater ASLR protection may determine where to place the trade-off. Signed-off-by: Daniel Cashman <dcashman@android.com> Signed-off-by: Daniel Cashman <dcashman@google.com> Bug: 27796957 Patchset: ASLR sysctl Change-Id: I1278914139a2e3910a301ab34755f409076768e7 Signed-off-by: Kees Cook <keescook@google.com>
2015-11-18Resolve kernel compilation warningsBrian Wood
This commit resolves the compile warnings seen when building the Intel Edison 3.10.x kernel. BUG=25764172 Change-Id: I655f702b24f9bcfb7655c57acfd8aafa69c52c0d Signed-off-by: Brian Wood <brian.j.wood@intel.com>
2015-09-23Merge tag 'v3.10.89' into edison-3.10.17Brian Wood
This is the 3.10.89 stable release Conflicts: arch/arm/mm/mmu.c arch/arm64/kernel/fpsimd.c arch/arm64/kernel/setup.c drivers/bluetooth/hci_ldisc.c drivers/hid/hid-logitech-dj.c drivers/hwmon/coretemp.c drivers/input/evdev.c drivers/mmc/card/block.c drivers/mmc/card/queue.h drivers/mmc/host/sdhci.c drivers/spi/spi-dw-mid.c fs/exec.c fs/ext4/ext4_jbd2.c fs/ext4/extents.c fs/ext4/indirect.c fs/ext4/inode.c fs/ext4/mballoc.c fs/ext4/namei.c fs/ext4/page-io.c fs/file_table.c fs/pstore/inode.c fs/pstore/ram.c fs/super.c include/linux/mm_types.h include/net/tcp.h include/sound/compress_driver.h kernel/fork.c kernel/futex.c mm/truncate.c net/ipv4/ping.c net/ipv4/sysctl_net_ipv4.c net/ipv6/route.c net/wireless/nl80211.c security/selinux/hooks.c sound/core/compress_offload.c
2015-09-22Merge branch 'google_source_common' into edison-3.10.17Brian Wood
Conflicts: arch/arm/mm/mmu.c crypto/Makefile drivers/misc/Kconfig drivers/misc/Makefile drivers/mmc/core/core.c drivers/net/wireless/Kconfig drivers/power/power_supply_core.c drivers/staging/android/logger.c fs/ext4/ext4_jbd2.c fs/ext4/inode.c fs/ext4/super.c fs/ext4/xattr.c include/linux/mmc/host.h include/linux/wlan_plat.h kernel/futex.c kernel/power/process.c net/bluetooth/l2cap_core.c net/ipv4/raw.c net/wireless/nl80211.c
2015-09-13perf: Fix fasync handling on inherited eventsPeter Zijlstra
commit fed66e2cdd4f127a43fd11b8d92a99bdd429528c upstream. Vince reported that the fasync signal stuff doesn't work proper for inherited events. So fix that. Installing fasync allocates memory and sets filp->f_flags |= FASYNC, which upon the demise of the file descriptor ensures the allocation is freed and state is updated. Now for perf, we can have the events stick around for a while after the original FD is dead because of references from child events. So we cannot copy the fasync pointer around. We can however consistently use the parent's fasync, as that will be updated. Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho deMelo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16signal: fix information leak in copy_siginfo_from_user32Amanieu d'Antras
commit 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309 upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16signal: fix information leak in copy_siginfo_to_userAmanieu d'Antras
commit 26135022f85105ad725cda103fa069e29e83bd16 upstream. This function may copy the si_addr_lsb, si_lower and si_upper fields to user mode when they haven't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-10genirq: Prevent resend to interrupts marked IRQ_NESTED_THREADThomas Gleixner
commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 upstream. The resend mechanism happily calls the interrupt handler of interrupts which are marked IRQ_NESTED_THREAD from softirq context. This can result in crashes because the interrupt handler is not the proper way to invoke the device handlers. They must be invoked via handle_nested_irq. Prevent the resend even if the interrupt has no valid parent irq set. Its better to have a lost interrupt than a crashing machine. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05wakeup_reason: use vsnprintf instead of snsprintf for vargs.Ruchi Kandoi
Bug: 22368519 Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
2015-08-03tracing: Have branch tracer use recursive field of task structSteven Rostedt (Red Hat)
commit 6224beb12e190ff11f3c7d4bf50cb2922878f600 upstream. Fengguang Wu's tests triggered a bug in the branch tracer's start up test when CONFIG_DEBUG_PREEMPT set. This was because that config adds some debug logic in the per cpu field, which calls back into the branch tracer. The branch tracer has its own recursive checks, but uses a per cpu variable to implement it. If retrieving the per cpu variable calls back into the branch tracer, you can see how things will break. Instead of using a per cpu variable, use the trace_recursion field of the current task struct. Simply set a bit when entering the branch tracing and clear it when leaving. If the bit is set on entry, just don't do the tracing. There's also the case with lockdep, as the local_irq_save() called before the recursion can also trigger code that can call back into the function. Changing that to a raw_local_irq_save() will protect that as well. This prevents the recursion and the inevitable crash that follows. Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03tracing/filter: Do not allow infix to exceed end of stringSteven Rostedt (Red Hat)
commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream. While debugging a WARN_ON() for filtering, I found that it is possible for the filter string to be referenced after its end. With the filter: # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter The filter_parse() function can call infix_get_op() which calls infix_advance() that updates the infix filter pointers for the cnt and tail without checking if the filter is already at the end, which will put the cnt to zero and the tail beyond the end. The loop then calls infix_next() that has ps->infix.cnt--; return ps->infix.string[ps->infix.tail++]; The cnt will now be below zero, and the tail that is returned is already passed the end of the filter string. So far the allocation of the filter string usually has some buffer that is zeroed out, but if the filter string is of the exact size of the allocated buffer there's no guarantee that the charater after the nul terminating character will be zero. Luckily, only root can write to the filter. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03tracing/filter: Do not WARN on operand count going below zeroSteven Rostedt (Red Hat)
commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-03__ptrace_may_access() should not deny sub-threadsMark Grondona
commit 73af963f9f3036dffed55c3a2898598186db1045 upstream. __ptrace_may_access() checks get_dumpable/ptrace_has_cap/etc if task != current, this can can lead to surprising results. For example, a sub-thread can't readlink("/proc/self/exe") if the executable is not readable. setup_new_exec()->would_dump() notices that inode_permission(MAY_READ) fails and then it does set_dumpable(suid_dumpable). After that get_dumpable() fails. (It is not clear why proc_pid_readlink() checks get_dumpable(), perhaps we could add PTRACE_MODE_NODUMPABLE) Change __ptrace_may_access() to use same_thread_group() instead of "task == current". Any security check is pointless when the tasks share the same ->mm. Signed-off-by: Mark Grondona <mgrondona@llnl.gov> Signed-off-by: Ben Woodard <woodard@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-29tracing: Have filter check for balanced opsSteven Rostedt
commit 2cf30dc180cea808077f003c5116388183e54f9e upstream. When the following filter is used it causes a warning to trigger: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: No error ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990() Modules linked in: bnep lockd grace bluetooth ... CPU: 3 PID: 1223 Comm: bash Tainted: G W 4.1.0-rc3-test+ #450 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0 0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea Call Trace: [<ffffffff816ed4f9>] dump_stack+0x4c/0x6e [<ffffffff8107fb07>] warn_slowpath_common+0x97/0xe0 [<ffffffff8136b46c>] ? _kstrtoull+0x2c/0x80 [<ffffffff8107fb6a>] warn_slowpath_null+0x1a/0x20 [<ffffffff81159065>] replace_preds+0x3c5/0x990 [<ffffffff811596b2>] create_filter+0x82/0xb0 [<ffffffff81159944>] apply_event_filter+0xd4/0x180 [<ffffffff81152bbf>] event_filter_write+0x8f/0x120 [<ffffffff811db2a8>] __vfs_write+0x28/0xe0 [<ffffffff811dda43>] ? __sb_start_write+0x53/0xf0 [<ffffffff812e51e0>] ? security_file_permission+0x30/0xc0 [<ffffffff811dc408>] vfs_write+0xb8/0x1b0 [<ffffffff811dc72f>] SyS_write+0x4f/0xb0 [<ffffffff816f5217>] system_call_fastpath+0x12/0x6a ---[ end trace e11028bd95818dcd ]--- Worse yet, reading the error message (the filter again) it says that there was no error, when there clearly was. The issue is that the code that checks the input does not check for balanced ops. That is, having an op between a closed parenthesis and the next token. This would only cause a warning, and fail out before doing any real harm, but it should still not caues a warning, and the error reported should work: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: Meaningless filter expression And give no kernel warning. Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> [ luis: backported to 3.16: - unconditionally decrement cnt as the OP_NOT logic was introduced only by e12c09cf3087 ("tracing: Add NOT to filtering logic") ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-22ring-buffer-benchmark: Fix the wrong sched_priority of producerWang Long
commit 108029323910c5dd1ef8fa2d10da1ce5fbce6e12 upstream. The producer should be used producer_fifo as its sched_priority, so correct it. Link: http://lkml.kernel.org/r/1433923957-67842-1-git-send-email-long.wanglong@huawei.com Signed-off-by: Wang Long <long.wanglong@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-08Merge remote-tracking branch 'ext4-3.19/for-android-3.10-common' into ↵Mohamad Ayyash
android-3.10
2015-06-04sched: cpufreq: update power usage only if cpufreq_stat is enabledAmit Pundir
Call acct_update_power() to track power usage of task only if CONFIG_CPU_FREQ_STAT is enabled, otherwise we run into following build failure: --------------- kernel/built-in.o: In function `account_user_time': kernel/sched/cputime.c:155: undefined reference to `acct_update_power' kernel/built-in.o: In function `__account_system_time': kernel/sched/cputime.c:208: undefined reference to `acct_update_power' make: *** [vmlinux] Error 1 --------------- Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
2015-06-02printk: port log_buf_clear API on kernel-next (for emmc_ipanic support)Yann Fouassier
Need to port log_buf_clear API on kernel-next in printk.c This is required to support emmc_ipanic Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
2015-06-02Edison kernel rebase: Correct merge errorsSaadi Maalem
While cherry-picking patches for Tangier support on top of 3.10.17 Yocto kernel, we have a few merge errors. Squashing the various corrections into this commit. Signed-off-by: Saadi Maalem <saadi.maalem@intel.com>
2015-06-02printk: fixing the deadlock when calling printk in nmi handleLiu, Chuansheng
Current printk implementation can not fully support that calling it in nmi handler for SMP arch. There is typical case in nmi handler function arch_trigger_all_cpu_backtrace_handler(). In my platform, there are 2 CPUs, when function arch_trigger_all_cpu_backtrace() is called, 2 CPUs will recevied the nmi interrupts, and the arch_trigger_all_cpu_backtrace_handler() will called on 2 CPUs: case1: CPU0 CPU1 calling arch_trigger_all_cpu_backtrace() calling printk, and has obtain the logbuf_lock nmi interrupt received nmi interrupt received call arch_trigger_all_cpu_backtrace_handler() call arch_trigger_all_cpu_backtrace_handler() Obtain arch_spin_lock(&lock); Waiting for arch_spin_lock(&lock); Continue to call printk() CPU0 will be blocked by logbuf_lock CPU1 is blocked by arch_spin_lock(&lock) The deadlock will be happening. case2: CPU0 CPU1:(run dmesg command) calling arch_trigger_all_cpu_backtrace() calling do_syslog Obtaining the logbuf_lock nmi interrupt received nmi interrupt received .... The dealock will happen also somtimes. I just write a simple interface to run the arch_trigger_all_cpu_backtrace_handler() every 5s, it will trigger dead lock many times. The solution is when printk is called in nmi handler, we will use trylock instead of lock. And in nmi handler, do the call the console write function because normal console write function include many spin locks also. This fix can confirm the traces in nmi handler can be output successfully almost. This fix is posted in the LKML also https://lkml.org/lkml/2012/7/4/273. Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com>
2015-06-02tracing: Fix potential out-of-bounds in trace_get_user()Steven Rostedt
commit 057db8488b53d5e4faa0cedb2f39d4ae75dfbdbb upstream. Andrey reported the following report: ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3 ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3) Accessed by thread T13003: #0 ffffffff810dd2da (asan_report_error+0x32a/0x440) #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40) #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20) #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260) #4 ffffffff812a1065 (__fput+0x155/0x360) #5 ffffffff812a12de (____fput+0x1e/0x30) #6 ffffffff8111708d (task_work_run+0x10d/0x140) #7 ffffffff810ea043 (do_exit+0x433/0x11f0) #8 ffffffff810eaee4 (do_group_exit+0x84/0x130) #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30) #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Allocated by thread T5167: #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0) #1 ffffffff8128337c (__kmalloc+0xbc/0x500) #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90) #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0) #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40) #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430) #6 ffffffff8129b668 (finish_open+0x68/0xa0) #7 ffffffff812b66ac (do_last+0xb8c/0x1710) #8 ffffffff812b7350 (path_openat+0x120/0xb50) #9 ffffffff812b8884 (do_filp_open+0x54/0xb0) #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0) #11 ffffffff8129d4b7 (SyS_open+0x37/0x50) #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Shadow bytes around the buggy address: ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap redzone: fa Heap kmalloc redzone: fb Freed heap region: fd Shadow gap: fe The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;' Although the crash happened in ftrace_regex_open() the real bug occurred in trace_get_user() where there's an incrementation to parser->idx without a check against the size. The way it is triggered is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop that reads the last character stores it and then breaks out because there is no more characters. Then the last character is read to determine what to do next, and the index is incremented without checking size. Then the caller of trace_get_user() usually nulls out the last character with a zero, but since the index is equal to the size, it writes a nul character after the allocated space, which can corrupt memory. Luckily, only root user has write access to this file. Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-02cgroup: fix to break the while loop in cgroup_attach_task() correctlyAnjana V Kumar
commit ea84753c98a7ac6b74e530b64c444a912b3835ca upstream. Both Anjana and Eunki reported a stall in the while_each_thread loop in cgroup_attach_task(). It's because, when we attach a single thread to a cgroup, if the cgroup is exiting or is already in that cgroup, we won't break the loop. If the task is already in the cgroup, the bug can lead to another thread being attached to the cgroup unexpectedly: # echo 5207 > tasks # cat tasks 5207 # echo 5207 > tasks # cat tasks 5207 5215 What's worse, if the task to be attached isn't the leader of the thread group, we might never exit the loop, hence cpu stall. Thanks for Oleg's analysis. This bug was introduced by commit 081aa458c38ba576bdd4265fc807fa95b48b9e79 ("cgroup: consolidate cgroup_attach_task() and cgroup_attach_proc()") [ lizf: - fixed the first continue, pointed out by Oleg, - rewrote changelog. ] Reported-by: Eunki Kim <eunki_kim@samsung.com> Reported-by: Anjana V Kumar <anjanavk12@gmail.com> Signed-off-by: Anjana V Kumar <anjanavk12@gmail.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-02Fix Critical Klocwork issuesPat Noziska
Fix Critical Klocwork issues in linux/kernel, mostly potential NULL pointer derefernces and potential buffer overflows. Signed-off-by: Pat Noziska <patrick.j.noziska@intel.com>
2015-06-02x86/irq: handle chained interrupts during IRQ migrationAxel Haslam
[Port to k3.10] Chained interrupt handlers dont have an irqaction and hence are not handled during migrating interrupts when some cores go offline. Handle this by introducing a irq_is_chained() check which is based on the the CHAINED flag being set for such interrupts. fixup_irq() can then handle such interrupts and not skip them over. Signed-off-by: Sundar Iyer <sundar.iyer@intel.com> Signed-off-by: Axel Haslam <axelx.haslam@intel.com> Signed-off-by: Bin Yang <bin.yang@intel.com>
2015-06-01sched: cpufreq: Adds a field cpu_power in the task_structRuchi Kandoi
cpu_power has been added to keep track of amount of power each task is consuming. cpu_power is updated whenever stime and utime are updated for a task. power is computed by taking into account the frequency at which the current core was running and the current for cpu actively running at hat frequency. Change-Id: Ic535941e7b339aab5cae9081a34049daeb44b248 Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
2015-05-28sched: add bit_wait_io for 3.18 ext4 backportTheodore Ts'o
Excerpted from commit 743162013: "sched: Remove proliferation of wait_on_bit() action functions" Change-Id: I56153d55a9af9f2911ed6ffb15d36ad89d45cd55 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Theodore Ts'o <tytso@google.com>
2015-05-18suspend: Return error when pending wakeup source is found.Ruchi Kandoi
If a wakeup source is found to be pending in the last stage of suspend after syscore suspend then the device doesn't suspend but the error is not propogated which causes an error in the accounting for the number of suspend aborts and successful suspends. Change-Id: Ib63b4ead755127eaf03e3b303aab3c782ad02ed1 Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
2015-05-17revert "softirq: Add support for triggering softirq work on softirqs"Christoph Hellwig
commit fc21c0cff2f425891b28ff6fb6b03b325c977428 upstream. This commit was incomplete in that code to remove items from the per-cpu lists was missing and never acquired a user in the 5 years it has been in the tree. We're going to implement what it seems to try to archive in a simpler way, and this code is in the way of doing so. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pan Xinhui <xinhuix.pan@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06ksoftirqd: Enable IRQs and call cond_resched() before poking RCUCalvin Owens
commit 28423ad283d5348793b0c45cc9b1af058e776fd6 upstream. While debugging an issue with excessive softirq usage, I encountered the following note in commit 3e339b5dae24a706 ("softirq: Use hotplug thread infrastructure"): [ paulmck: Call rcu_note_context_switch() with interrupts enabled. ] ...but despite this note, the patch still calls RCU with IRQs disabled. This seemingly innocuous change caused a significant regression in softirq CPU usage on the sending side of a large TCP transfer (~1 GB/s): when introducing 0.01% packet loss, the softirq usage would jump to around 25%, spiking as high as 50%. Before the change, the usage would never exceed 5%. Moving the call to rcu_note_context_switch() after the cond_sched() call, as it was originally before the hotplug patch, completely eliminated this problem. Signed-off-by: Calvin Owens <calvinowens@fb.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06ptrace: fix race between ptrace_resume() and wait_task_stopped()Oleg Nesterov
commit b72c186999e689cb0b055ab1c7b3cd8fffbeb5ed upstream. ptrace_resume() is called when the tracee is still __TASK_TRACED. We set tracee->exit_code and then wake_up_state() changes tracee->state. If the tracer's sub-thread does wait() in between, task_stopped_code(ptrace => T) wrongly looks like another report from tracee. This confuses debugger, and since wait_task_stopped() clears ->exit_code the tracee can miss a signal. Test-case: #include <stdio.h> #include <unistd.h> #include <sys/wait.h> #include <sys/ptrace.h> #include <pthread.h> #include <assert.h> int pid; void *waiter(void *arg) { int stat; for (;;) { assert(pid == wait(&stat)); assert(WIFSTOPPED(stat)); if (WSTOPSIG(stat) == SIGHUP) continue; assert(WSTOPSIG(stat) == SIGCONT); printf("ERR! extra/wrong report:%x\n", stat); } } int main(void) { pthread_t thread; pid = fork(); if (!pid) { assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0); for (;;) kill(getpid(), SIGHUP); } assert(pthread_create(&thread, NULL, waiter, NULL) == 0); for (;;) ptrace(PTRACE_CONT, pid, 0, SIGCONT); return 0; } Note for stable: the bug is very old, but without 9899d11f6544 "ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL" the fix should use lock_task_sighand(child). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Pavel Labath <labath@google.com> Tested-by: Pavel Labath <labath@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06ring-buffer: Replace this_cpu_*() with __this_cpu_*()Steven Rostedt
commit 80a9b64e2c156b6523e7a01f2ba6e5d86e722814 upstream. It has come to my attention that this_cpu_read/write are horrible on architectures other than x86. Worse yet, they actually disable preemption or interrupts! This caused some unexpected tracing results on ARM. 101.356868: preempt_count_add <-ring_buffer_lock_reserve 101.356870: preempt_count_sub <-ring_buffer_lock_reserve The ring_buffer_lock_reserve has recursion protection that requires accessing a per cpu variable. But since preempt_disable() is traced, it too got traced while accessing the variable that is suppose to prevent recursion like this. The generic version of this_cpu_read() and write() are: #define this_cpu_generic_read(pcp) \ ({ typeof(pcp) ret__; \ preempt_disable(); \ ret__ = *this_cpu_ptr(&(pcp)); \ preempt_enable(); \ ret__; \ }) #define this_cpu_generic_to_op(pcp, val, op) \ do { \ unsigned long flags; \ raw_local_irq_save(flags); \ *__this_cpu_ptr(&(pcp)) op val; \ raw_local_irq_restore(flags); \ } while (0) Which is unacceptable for locations that know they are within preempt disabled or interrupt disabled locations. Paul McKenney stated that __this_cpu_() versions produce much better code on other architectures than this_cpu_() does, if we know that the call is done in a preempt disabled location. I also changed the recursive_unlock() to use two local variables instead of accessing the per_cpu variable twice. Link: http://lkml.kernel.org/r/20150317114411.GE3589@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/20150317104038.312e73d1@gandalf.local.home Acked-by: Christoph Lameter <cl@linux.com> Reported-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Tested-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-29move d_rcu from overlapping d_child to overlapping d_aliasAl Viro
commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Ben Hutchings <ben@decadent.org.uk> [hujianyang: Backported to 3.10 refer to the work of Ben Hutchings in 3.2: - Apply name changes in all the different places we use d_alias and d_child - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()] Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-19console: Fix console name size mismatchPeter Hurley
commit 30a22c215a0007603ffc08021f2e8b64018517dd upstream. commit 6ae9200f2cab7 ("enlarge console.name") increased the storage for the console name to 16 bytes, but not the corresponding struct console_cmdline::name storage. Console names longer than 8 bytes cause read beyond end-of-string and failure to match console; I'm not sure if there are other unexpected consequences. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13perf: Fix irq_work 'tail' recursionPeter Zijlstra
commit d525211f9d1be8b523ec7633f080f2116f5ea536 upstream. Vince reported a watchdog lockup like: [<ffffffff8115e114>] perf_tp_event+0xc4/0x210 [<ffffffff810b4f8a>] perf_trace_lock+0x12a/0x160 [<ffffffff810b7f10>] lock_release+0x130/0x260 [<ffffffff816c7474>] _raw_spin_unlock_irqrestore+0x24/0x40 [<ffffffff8107bb4d>] do_send_sig_info+0x5d/0x80 [<ffffffff811f69df>] send_sigio_to_task+0x12f/0x1a0 [<ffffffff811f71ce>] send_sigio+0xae/0x100 [<ffffffff811f72b7>] kill_fasync+0x97/0xf0 [<ffffffff8115d0b4>] perf_event_wakeup+0xd4/0xf0 [<ffffffff8115d103>] perf_pending_event+0x33/0x60 [<ffffffff8114e3fc>] irq_work_run_list+0x4c/0x80 [<ffffffff8114e448>] irq_work_run+0x18/0x40 [<ffffffff810196af>] smp_trace_irq_work_interrupt+0x3f/0xc0 [<ffffffff816c99bd>] trace_irq_work_interrupt+0x6d/0x80 Which is caused by an irq_work generating new irq_work and therefore not allowing forward progress. This happens because processing the perf irq_work triggers another perf event (tracepoint stuff) which in turn generates an irq_work ad infinitum. Avoid this by raising the recursion counter in the irq_work -- which effectively disables all software events (including tracepoints) from actually triggering again. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20150219170311.GH21418@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-09Power: Report suspend times from last_suspend_timejinqian
This node epxorts two values separated by space. From left to right: 1. time spent in suspend/resume process 2. time spent sleep in suspend state Change-Id: I2cb9a9408a5fd12166aaec11b935a0fd6a408c63
2015-03-26workqueue: fix hang involving racing cancel[_delayed]_work_sync()'s for ↵Tejun Heo
PREEMPT_NONE commit 8603e1b30027f943cc9c1eef2b291d42c3347af1 upstream. cancel[_delayed]_work_sync() are implemented using __cancel_work_timer() which grabs the PENDING bit using try_to_grab_pending() and then flushes the work item with PENDING set to prevent the on-going execution of the work item from requeueing itself. try_to_grab_pending() can always grab PENDING bit without blocking except when someone else is doing the above flushing during cancelation. In that case, try_to_grab_pending() returns -ENOENT. In this case, __cancel_work_timer() currently invokes flush_work(). The assumption is that the completion of the work item is what the other canceling task would be waiting for too and thus waiting for the same condition and retrying should allow forward progress without excessive busy looping Unfortunately, this doesn't work if preemption is disabled or the latter task has real time priority. Let's say task A just got woken up from flush_work() by the completion of the target work item. If, before task A starts executing, task B gets scheduled and invokes __cancel_work_timer() on the same work item, its try_to_grab_pending() will return -ENOENT as the work item is still being canceled by task A and flush_work() will also immediately return false as the work item is no longer executing. This puts task B in a busy loop possibly preventing task A from executing and clearing the canceling state on the work item leading to a hang. task A task B worker executing work __cancel_work_timer() try_to_grab_pending() set work CANCELING flush_work() block for work completion completion, wakes up A __cancel_work_timer() while (forever) { try_to_grab_pending() -ENOENT as work is being canceled flush_work() false as work is no longer executing } This patch removes the possible hang by updating __cancel_work_timer() to explicitly wait for clearing of CANCELING rather than invoking flush_work() after try_to_grab_pending() fails with -ENOENT. Link: http://lkml.kernel.org/g/20150206171156.GA8942@axis.com v3: bit_waitqueue() can't be used for work items defined in vmalloc area. Switched to custom wake function which matches the target work item and exclusive wait and wakeup. v2: v1 used wake_up() on bit_waitqueue() which leads to NULL deref if the target bit waitqueue has wait_bit_queue's on it. Use DEFINE_WAIT_BIT() and __wake_up_bit() instead. Reported by Tomeu Vizoso. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Rabin Vincent <rabin.vincent@axis.com> Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com> Tested-by: Jesper Nilsson <jesper.nilsson@axis.com> Tested-by: Rabin Vincent <rabin.vincent@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-18PM / QoS: remove duplicate call to pm_qos_update_targetMichael Scott
In 3.10.y backport patch 1dba303727f52ea062580b0a9b3f0c3b462769cf, the logic to call pm_qos_update_target was moved to __pm_qos_update_request. However, the original code was left in function pm_qos_update_request. Currently, if pm_qos_update_request is called where new_value != req->node.prio then pm_qos_update_target will be called twice in a row. Once in pm_qos_update_request and then again in the following call to _pm_qos_update_request. Removing the left over code from pm_qos_update_request stops this second call to pm_qos_update_target where the work of removing / re-adding the new_value in the constraints list would be duplicated. Signed-off-by: Michael Scott <michael.scott@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-13Revert "Revert "timer_list: Convert timer list to be a proper seq_file""Bruce Ashfield
This reverts commit 1c0d1d837f02ef6a3399ce250a409205381ca89d. Change-Id: I4bc1eb0d751536eb33f4e7159b05644cec275fc4
2015-03-13Revert "Revert "timer_list: Split timer_list_show_tickdevices""Bruce Ashfield
This reverts commit 7144bcc4b8091675bfcf1941479067857b6242da.
2015-03-13Revert "timer_list: Split timer_list_show_tickdevices"Tom Zanussi
This reverts commit 60cf7ea849e77c8782dee147cfb8c38d1984236e. This is a temporary workaround for the dropbearkey hang issue in 3.10.
2015-03-13Revert "timer_list: Convert timer list to be a proper seq_file"Tom Zanussi
This reverts commit b3956a896ea57f25cacd74708b8fab611543a81d. This is a temporary workaround for the dropbearkey hang issue in 3.10. Change-Id: I914528e75fe81dc712aca90f3aa0f8030a03a30f
2015-03-06ntp: Fixup adjtimex freq validation on 32-bit systemsJohn Stultz
commit 29183a70b0b828500816bd794b3fe192fce89f73 upstream. Additional validation of adjtimex freq values to avoid potential multiplication overflows were added in commit 5e5aeb4367b (time: adjtimex: Validate the ADJ_FREQUENCY values) Unfortunately the patch used LONG_MAX/MIN instead of LLONG_MAX/MIN, which was fine on 64-bit systems, but being much smaller on 32-bit systems caused false positives resulting in most direct frequency adjustments to fail w/ EINVAL. ntpd only does direct frequency adjustments at startup, so the issue was not as easily observed there, but other time sync applications like ptpd and chrony were more effected by the bug. See bugs: https://bugzilla.kernel.org/show_bug.cgi?id=92481 https://bugzilla.redhat.com/show_bug.cgi?id=1188074 This patch changes the checks to use LLONG_MAX for clarity, and additionally the checks are disabled on 32-bit systems since LLONG_MAX/PPM_SCALE is always larger then the 32-bit long freq value, so multiplication overflows aren't possible there. Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Reported-by: George Joseph <george.joseph@fairview5.com> Tested-by: George Joseph <george.joseph@fairview5.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sasha Levin <sasha.levin@oracle.com> Link: http://lkml.kernel.org/r/1423553436-29747-1-git-send-email-john.stultz@linaro.org [ Prettified the changelog and the comments a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06kdb: fix incorrect counts in KDB summary command outputJay Lan
commit 146755923262037fc4c54abc28c04b1103f3cc51 upstream. The output of KDB 'summary' command should report MemTotal, MemFree and Buffers output in kB. Current codes report in unit of pages. A define of K(x) as is defined in the code, but not used. This patch would apply the define to convert the values to kB. Please include me on Cc on replies. I do not subscribe to linux-kernel. Signed-off-by: Jay Lan <jlan@sgi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06tracing: Fix unmapping loop in tracing_mark_writeVikram Mulukutla
commit 7215853e985a4bef1a6c14e00e89dfec84f1e457 upstream. Commit 6edb2a8a385f0cdef51dae37ff23e74d76d8a6ce introduced an array map_pages that contains the addresses returned by kmap_atomic. However, when unmapping those pages, map_pages[0] is unmapped before map_pages[1], breaking the nesting requirement as specified in the documentation for kmap_atomic/kunmap_atomic. This was caught by the highmem debug code present in kunmap_atomic. Fix the loop to do the unmapping properly. Link: http://lkml.kernel.org/r/1418871056-6614-1-git-send-email-markivx@codeaurora.org Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Lime Yang <limey@codeaurora.org> Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-11smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()Lai Jiangshan
commit 4bee96860a65c3a62d332edac331b3cf936ba3ad upstream. The following race exists in the smpboot percpu threads management: CPU0 CPU1 cpu_up(2) get_online_cpus(); smpboot_create_threads(2); smpboot_register_percpu_thread(); for_each_online_cpu(); __smpboot_create_thread(); __cpu_up(2); This results in a missing per cpu thread for the newly onlined cpu2 and in a NULL pointer dereference on a consecutive offline of that cpu. Proctect smpboot_register_percpu_thread() with get_online_cpus() to prevent that. [ tglx: Massaged changelog and removed the change in smpboot_unregister_percpu_thread() because that's an optimization and therefor not stable material. ] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/1406777421-12830-1-git-send-email-laijs@cn.fujitsu.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-05workqueue: fix subtle pool management issue which can stall whole worker_poolTejun Heo
commit 29187a9eeaf362d8422e62e17a22a6e115277a49 upstream. A worker_pool's forward progress is guaranteed by the fact that the last idle worker assumes the manager role to create more workers and summon the rescuers if creating workers doesn't succeed in timely manner before proceeding to execute work items. This manager role is implemented in manage_workers(), which indicates whether the worker may proceed to work item execution with its return value. This is necessary because multiple workers may contend for the manager role, and, if there already is a manager, others should proceed to work item execution. Unfortunately, the function also indicates that the worker may proceed to work item execution if need_to_create_worker() is false at the head of the function. need_to_create_worker() tests the following conditions. pending work items && !nr_running && !nr_idle The first and third conditions are protected by pool->lock and thus won't change while holding pool->lock; however, nr_running can change asynchronously as other workers block and resume and while it's likely to be zero, as someone woke this worker up in the first place, some other workers could have become runnable inbetween making it non-zero. If this happens, manage_worker() could return false even with zero nr_idle making the worker, the last idle one, proceed to execute work items. If then all workers of the pool end up blocking on a resource which can only be released by a work item which is pending on that pool, the whole pool can deadlock as there's no one to create more workers or summon the rescuers. This patch fixes the problem by removing the early exit condition from maybe_create_worker() and making manage_workers() return false iff there's already another manager, which ensures that the last worker doesn't start executing work items. We can leave the early exit condition alone and just ignore the return value but the only reason it was put there is because the manage_workers() used to perform both creations and destructions of workers and thus the function may be invoked while the pool is trying to reduce the number of workers. Now that manage_workers() is called only when more workers are needed, the only case this early exit condition is triggered is rare race conditions rendering it pointless. Tested with simulated workload and modified workqueue code which trigger the pool deadlock reliably without this patch. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Eric Sandeen <sandeen@sandeen.net> Link: http://lkml.kernel.org/g/54B019F4.8030009@sandeen.net Cc: Dave Chinner <david@fromorbit.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-29time: adjtimex: Validate the ADJ_FREQUENCY valuesSasha Levin
commit 5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f upstream. Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> [jstultz: Fix up bug for negative values and drop redunent cap check] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-29time: settimeofday: Validate the values of tv from userSasha Levin
commit 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 upstream. An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> [jstultz: include trivial milisecond->microsecond correction noticed by Andy] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>