| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.6 197/203] tmpfs: dont undo fallocate past its last page | Date | Mon, 25 Jul 2016 13:56:52 -0700 |
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4.6-stable review patch. If anyone has any objections, please let me know.
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From: Anthony Romano <anthony.romano@coreos.com>
commit b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe upstream.
When fallocate is interrupted it will undo a range that extends one byte past its range of allocated pages. This can corrupt an in-use page by zeroing out its first byte. Instead, undo using the inclusive byte range.
Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure") Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@coreos.com Signed-off-by: Anthony Romano <anthony.romano@coreos.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Brandon Philips <brandon@ifup.co> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/shmem.c +++ b/mm/shmem.c @@ -2238,7 +2238,7 @@ static long shmem_fallocate(struct file /* Remove the !PageUptodate pages we added */ shmem_undo_range(inode, (loff_t)start << PAGE_SHIFT, - (loff_t)index << PAGE_SHIFT, true); + ((loff_t)index << PAGE_SHIFT) - 1, true); goto undone; }
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