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| author | Kees Cook <keescook@chromium.org> | 2015-02-17 13:48:00 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@google.com> | 2016-04-08 20:49:38 +0000 |
| commit | 6a8aa6ba8bfec89ad16f964e42ac11d905ad7a1c (patch) | |
| tree | 1e634486615d455ca9957f7faf44eefb2c5d99da | |
| parent | 3eccfae5bcffd92126dd3c8c7700311c30cdd9fb (diff) | |
| download | edison-v3.10-6a8aa6ba8bfec89ad16f964e42ac11d905ad7a1c.tar.gz | |
BACKPORT: seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO
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
| -rw-r--r-- | kernel/seccomp.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 1fbb1a2bc45..ba54fc2f417 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -600,7 +600,9 @@ int __secure_computing(int this_syscall) ret &= SECCOMP_RET_ACTION; switch (ret) { case SECCOMP_RET_ERRNO: - /* Set the low-order 16-bits as a errno. */ + /* Set low-order bits as an errno, capped at MAX_ERRNO. */ + if (data > MAX_ERRNO) + data = MAX_ERRNO; syscall_set_return_value(current, regs, -data, 0); goto skip; |