Messages in this thread Patch in this message | | | From | Jesper Juhl <> | Subject | [PATCH][XFS][resend] fix memory leak in xfs_inactive() | Date | Sun, 1 Jul 2007 01:16:51 +0200 |
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(this is back from May 16 2007, resending since it doesn't look like the patch ever made it in anywhere)
The Coverity checker found a memory leak in xfs_inactive().
The offending code is this bit :
1671 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
At conditional (1): "truncate != 0" taking true path
1672 if (truncate) { 1673 /* 1674 * Do the xfs_itruncate_start() call before 1675 * reserving any log space because itruncate_start 1676 * will call into the buffer cache and we can't 1677 * do that within a transaction. 1678 */ 1679 xfs_ilock(ip, XFS_IOLOCK_EXCL); 1680 1681 error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0);
At conditional (2): "error != 0" taking true path
1682 if (error) { 1683 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
Event leaked_storage: Returned without freeing storage "tp" Also see events: [alloc_fn][var_assign]
1684 return VN_INACTIVE_CACHE; 1685 }
So, the code allocates a transaction, but in the case where 'truncate' is !=0 and xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); happens to return an error, we'll just return from the function without dealing with the memory allocated byxfs_trans_alloc() and assigned to 'tp', thus it'll be orphaned/leaked - not good.
The bug was introduced by this commit: http://git2.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d3cf209476b72c83907a412b6708c5e498410aa7
The patch below is
From: Dave Chinner <dgc@sgi.com> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> --- fs/xfs/xfs_vnodeops.c | 1 + 1 file changed, 1 insertion(+)
Index: 2.6.x-xfs-new/fs/xfs/xfs_vnodeops.c =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/xfs_vnodeops.c 2007-05-11 16:04:03.000000000 +1000 +++ 2.6.x-xfs-new/fs/xfs/xfs_vnodeops.c 2007-05-17 12:37:25.671399078 +1000 @@ -1710,6 +1710,7 @@ xfs_inactive( error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); if (error) { + xfs_trans_cancel(tp, 0); xfs_iunlock(ip, XFS_IOLOCK_EXCL); return VN_INACTIVE_CACHE; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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