Messages in this thread Patch in this message | | | Date | Wed, 16 Apr 2014 10:54:34 -0700 | From | Kees Cook <> | Subject | [PATCH v2] seccomp: fix memory leak on filter attach |
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This sets the correct error code when final filter memory is unavailable, and frees the raw filter no matter what.
unreferenced object 0xffff8800d6ea4000 (size 512): comm "sshd", pid 278, jiffies 4294898315 (age 46.653s) hex dump (first 32 bytes): 21 00 00 00 04 00 00 00 15 00 01 00 3e 00 00 c0 !...........>... 06 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00 ........!....... backtrace: [<ffffffff8151414e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff811a3a40>] __kmalloc+0x280/0x320 [<ffffffff8110842e>] prctl_set_seccomp+0x11e/0x3b0 [<ffffffff8107bb6b>] SyS_prctl+0x3bb/0x4a0 [<ffffffff8152ef2d>] system_call_fastpath+0x1a/0x1f [<ffffffffffffffff>] 0xffffffffffffffff
Reported-by: Masami Ichikawa <masami256@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Masami Ichikawa <masami256@gmail.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> --- David, since you just pushed the a0-a5 fix, can you push this fix as well?
v2: - drop stable cc, not needed. - added tested-by and acked-by. --- kernel/seccomp.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 590c37925084..b35c21503a36 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -255,6 +255,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) goto free_prog; /* Allocate a new seccomp_filter */ + ret = -ENOMEM; filter = kzalloc(sizeof(struct seccomp_filter) + sizeof(struct sock_filter_int) * new_len, GFP_KERNEL|__GFP_NOWARN); @@ -264,6 +265,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) ret = sk_convert_filter(fp, fprog->len, filter->insnsi, &new_len); if (ret) goto free_filter; + kfree(fp); atomic_set(&filter->usage, 1); filter->len = new_len; -- 1.7.9.5
-- Kees Cook Chrome OS Security
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