Messages in this thread | | | Date | Thu, 23 Jun 2011 14:19:50 -0400 | Subject | Re: [34-longterm 238/247] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 | From | Paul Gortmaker <> |
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On Thu, Jun 23, 2011 at 1:49 PM, Dan Rosenberg <drosenberg@vsecurity.com> wrote: > On Thu, 2011-06-23 at 13:35 -0400, Paul Gortmaker wrote: >> From: Dan Rosenberg <drosenberg@vsecurity.com> >> >> ------------------- >> This is a commit scheduled for the next v2.6.34 longterm release. >> If you see a problem with using this for longterm, please comment. >> ------------------- >> >> commit 3a3675b7f23f83ca8c67c9c2b6edf707fd28d1ba upstream. >> >> The FSGEOMETRY_V1 ioctl (and its compat equivalent) calls out to >> xfs_fs_geometry() with a version number of 3. This code path does not >> fill in the logsunit member of the passed xfs_fsop_geom_t, leading to >> the leaking of four bytes of uninitialized stack data to potentially >> unprivileged callers. >> >> v2 switches to memset() to avoid future issues if structure members >> change, on suggestion of Dave Chinner. >> >> Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> >> Reviewed-by: Eugene Teo <eugeneteo@kernel.org> >> Signed-off-by: Alex Elder <aelder@sgi.com> >> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> >> --- >> fs/xfs/xfs_fsops.c | 3 +++ >> 1 files changed, 3 insertions(+), 0 deletions(-) >> >> diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c >> index 37a6f62..4e7f02b 100644 >> --- a/fs/xfs/xfs_fsops.c >> +++ b/fs/xfs/xfs_fsops.c >> @@ -57,6 +57,9 @@ xfs_fs_geometry( >> xfs_fsop_geom_t *geo, >> int new_version) >> { >> + >> + memset(geo, 0, sizeof(*geo)); >> + >> geo->blocksize = mp->m_sb.sb_blocksize; >> geo->rtextsize = mp->m_sb.sb_rextsize; >> geo->agblocks = mp->m_sb.sb_agblocks; >> -- >> 1.7.4.4 > > This introduced a regression which was fixed by commit > af24ee9ea8d532e16883251a6684dfa1be8eec29.
Thanks Dan,
Fix queued and will appear shortly here.
http://git.kernel.org/?p=linux/kernel/git/longterm/longterm-queue-2.6.34.git;a=summary
Paul.
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