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| author | Waiman Long <longman@redhat.com> | 2018-10-30 15:07:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-31 08:54:14 -0700 |
| commit | 8c81ddd2acd2c10979f5a64f6784ce7c6717495e (patch) | |
| tree | 753eefd7695e89bd0667bb877123be642c134642 /ipc/util.h | |
| parent | 6730e6580177d13f4612767873cb5a533ad63c61 (diff) | |
| download | lwn-8c81ddd2acd2c10979f5a64f6784ce7c6717495e.tar.gz lwn-8c81ddd2acd2c10979f5a64f6784ce7c6717495e.zip | |
ipc: IPCMNI limit check for semmni
For SysV semaphores, the semmni value is the last part of the 4-element
sem number array. To make semmni behave in a similar way to msgmni and
shmmni, we can't directly use the _minmax handler. Instead, a special sem
specific handler is added to check the last argument to make sure that it
is limited to the [0, IPCMNI] range. An error will be returned if this is
not the case.
Link: http://lkml.kernel.org/r/1536352137-12003-3-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/util.h')
| -rw-r--r-- | ipc/util.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/ipc/util.h b/ipc/util.h index 1ee81bce25e9..d768fdbed515 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -217,6 +217,15 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); +static inline int sem_check_semmni(struct ipc_namespace *ns) { + /* + * Check semmni range [0, IPCMNI] + * semmni is the last element of sem_ctls[4] array + */ + return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > IPCMNI)) + ? -ERANGE : 0; +} + #ifdef CONFIG_COMPAT #include <linux/compat.h> struct compat_ipc_perm { |