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| author | Michal Hocko <mhocko@suse.com> | 2017-05-08 15:57:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-08 17:15:12 -0700 |
| commit | 81be3dee96346fbe08c31be5ef74f03f6b63cf68 (patch) | |
| tree | 0da1345c2f9b956b944c442e1df062dce6d692f9 /fs/xattr.c | |
| parent | 847f716f9ec2c61f57690c871a307f1349d472d0 (diff) | |
| download | linux-81be3dee96346fbe08c31be5ef74f03f6b63cf68.tar.gz linux-81be3dee96346fbe08c31be5ef74f03f6b63cf68.tar.bz2 linux-81be3dee96346fbe08c31be5ef74f03f6b63cf68.zip | |
fs/xattr.c: zero out memory copied to userspace in getxattr
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>
Cc: <stable@vger.kernel.org> [3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/xattr.c')
| -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 7e3317cf4045..94f49a082dd2 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -530,7 +530,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value, size = XATTR_SIZE_MAX; kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); if (!kvalue) { - kvalue = vmalloc(size); + kvalue = vzalloc(size); if (!kvalue) return -ENOMEM; } |