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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2013-10-31 21:00:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-20 07:45:08 -0800 |
| commit | f75eb9d4085192dc58c30a9384cf4496194be851 (patch) | |
| tree | 1257d111f27a5cea0c92358ad8e55dd87545213e | |
| parent | 7e767aae0ed129f6e67f5fec09fa870be452788c (diff) | |
| download | lwn-f75eb9d4085192dc58c30a9384cf4496194be851.tar.gz lwn-f75eb9d4085192dc58c30a9384cf4496194be851.zip | |
xfs: underflow bug in xfs_attrlist_by_handle()
commit 31978b5cc66b8ba8a7e8eef60b12395d41b7b890 upstream.
If we allocate less than sizeof(struct attrlist) then we end up
corrupting memory or doing a ZERO_PTR_SIZE dereference.
This can only be triggered with CAP_SYS_ADMIN.
Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/xfs/xfs_ioctl.c | 3 | ||||
| -rw-r--r-- | fs/xfs/xfs_ioctl32.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index ca01d830e989..83dfe6e73235 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -409,7 +409,8 @@ xfs_attrlist_by_handle( return -XFS_ERROR(EPERM); if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t))) return -XFS_ERROR(EFAULT); - if (al_hreq.buflen > XATTR_LIST_MAX) + if (al_hreq.buflen < sizeof(struct attrlist) || + al_hreq.buflen > XATTR_LIST_MAX) return -XFS_ERROR(EINVAL); /* diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c index c0c66259cc91..68799d7f02cc 100644 --- a/fs/xfs/xfs_ioctl32.c +++ b/fs/xfs/xfs_ioctl32.c @@ -359,7 +359,8 @@ xfs_compat_attrlist_by_handle( if (copy_from_user(&al_hreq, arg, sizeof(compat_xfs_fsop_attrlist_handlereq_t))) return -XFS_ERROR(EFAULT); - if (al_hreq.buflen > XATTR_LIST_MAX) + if (al_hreq.buflen < sizeof(struct attrlist) || + al_hreq.buflen > XATTR_LIST_MAX) return -XFS_ERROR(EINVAL); /* |