diff options
| author | Kees Cook <keescook@chromium.org> | 2016-01-20 15:00:45 -0800 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-07-31 13:37:49 -0400 |
| commit | a97964ce4a04d077af3ff2203db769f48ee3ca98 (patch) | |
| tree | d113d625c814870cd6b625efb66152246b09df2f /Documentation | |
| parent | 84bad5618d67028c7f4342351fa7a5961413ed4c (diff) | |
sysctl: enable strict writes
[ Upstream commit 41662f5cc55335807d39404371cfcbb1909304c4 ]
SYSCTL_WRITES_WARN was added in commit f4aacea2f5d1 ("sysctl: allow for
strict write position handling"), and released in v3.16 in August of
2014. Since then I can find only 1 instance of non-zero offset
writing[1], and it was fixed immediately in CRIU[2]. As such, it
appears safe to flip this to the strict state now.
[1] https://www.google.com/search?q="when%20file%20position%20was%20not%200"
[2] http://lists.openvz.org/pipermail/criu/2015-April/019819.html
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index c831001c45f1..4c88aa047790 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -798,14 +798,13 @@ via the /proc/sys interface: Each write syscall must fully contain the sysctl value to be written, and multiple writes on the same sysctl file descriptor will rewrite the sysctl value, regardless of file position. - 0 - (default) Same behavior as above, but warn about processes that - perform writes to a sysctl file descriptor when the file position - is not 0. - 1 - Respect file position when writing sysctl strings. Multiple writes - will append to the sysctl value buffer. Anything past the max length - of the sysctl value buffer will be ignored. Writes to numeric sysctl - entries must always be at file position 0 and the value must be - fully contained in the buffer sent in the write syscall. + 0 - Same behavior as above, but warn about processes that perform writes + to a sysctl file descriptor when the file position is not 0. + 1 - (default) Respect file position when writing sysctl strings. Multiple + writes will append to the sysctl value buffer. Anything past the max + length of the sysctl value buffer will be ignored. Writes to numeric + sysctl entries must always be at file position 0 and the value must + be fully contained in the buffer sent in the write syscall. ============================================================== |