| Date | Fri, 17 Aug 2012 12:38:55 -0300 | From | Herton Ronaldo Krzesinski <> | Subject | Re: [v2.6.34-stable 013/165] xfs: Fix possible memory corruption in xfs_readlink |
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On Wed, Aug 15, 2012 at 03:45:57PM -0400, Paul Gortmaker wrote: > From: Carlos Maiolino <cmaiolino@redhat.com> > > ------------------- > This is a commit scheduled for the next v2.6.34 longterm release. > http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git > If you see a problem with using this for longterm, please comment. > ------------------- > > commit b52a360b2aa1c59ba9970fb0f52bbb093fcc7a24 upstream. > > Fixes a possible memory corruption when the link is larger than > MAXPATHLEN and XFS_DEBUG is not enabled. This also remove the > S_ISLNK assert, since the inode mode is checked previously in > xfs_readlink_by_handle() and via VFS. > > Updated to address concerns raised by Ben Hutchings about the loose > attention paid to 32- vs 64-bit values, and the lack of handling a > potentially negative pathlen value: > - Changed type of "pathlen" to be xfs_fsize_t, to match that of > ip->i_d.di_size > - Added checking for a negative pathlen to the too-long pathlen > test, and generalized the message that gets reported in that case > to reflect the change > As a result, if a negative pathlen were encountered, this function > would return EFSCORRUPTED (and would fail an assertion for a debug > build)--just as would a too-long pathlen. > > Signed-off-by: Alex Elder <aelder@sgi.com> > Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > [PG: no xfs_alert in 2.6.34; use xfs_fs_cmn_err(CE_ALERT, ...) instead] > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> [...]
commit 9b025eb3a89e041bab6698e3858706be2385d692 ("xfs: Fix missing xfs_iunlock() on error recovery path in xfs_readlink()") addresses a regression with this change, something to consider for inclusion too.
-- []'s Herton
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