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| author | Michal Hocko <mhocko@suse.com> | 2017-05-08 15:57:24 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-08-26 02:14:47 +0100 |
| commit | 0dc00866575aef50d8c15fda0d6b220630d4fde5 (patch) | |
| tree | 5fca29a0f4c17172aba222adece32ec1edfb1eb1 /fs | |
| parent | 988a86df7d858492574003b624c9db7a9c9e3d9c (diff) | |
| download | linux-stable-0dc00866575aef50d8c15fda0d6b220630d4fde5.tar.gz linux-stable-0dc00866575aef50d8c15fda0d6b220630d4fde5.tar.bz2 linux-stable-0dc00866575aef50d8c15fda0d6b220630d4fde5.zip | |
fs/xattr.c: zero out memory copied to userspace in getxattr
commit 81be3dee96346fbe08c31be5ef74f03f6b63cf68 upstream.
getxattr uses vmalloc to allocate memory if kzalloc fails. This is
filled by vfs_getxattr and then copied to the userspace. vmalloc,
however, doesn't zero out the memory so if the specific implementation
of the xattr handler is sloppy we can theoretically expose a kernel
memory. There is no real sign this is really the case but let's make
sure this will not happen and use vzalloc instead.
Fixes: 779302e67835 ("fs/xattr.c:getxattr(): improve handling of allocation failures")
Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/xattr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xattr.c b/fs/xattr.c index c69e6d43a0d2..7325e2ecbae9 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -455,7 +455,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value, size = XATTR_SIZE_MAX; kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); if (!kvalue) { - vvalue = vmalloc(size); + vvalue = vzalloc(size); if (!vvalue) return -ENOMEM; kvalue = vvalue; |