| Message ID | 200904092032.n39KWqYF011512@imap1.linux-foundation.org |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
diff -puN fs/ext3/inode.c~ext3-fix-chain-verification-in-ext3_get_blocks fs/ext3/inode.c --- a/fs/ext3/inode.c~ext3-fix-chain-verification-in-ext3_get_blocks +++ a/fs/ext3/inode.c @@ -820,7 +820,7 @@ int ext3_get_blocks_handle(handle_t *han while (count < maxblocks && count <= blocks_to_boundary) { ext3_fsblk_t blk; - if (!verify_chain(chain, partial)) { + if (!verify_chain(chain, chain + depth - 1)) { /* * Indirect block might be removed by * truncate while we were reading it.
The patch titled ext3: fix chain verification in ext3_get_blocks() has been added to the -mm tree. Its filename is ext3-fix-chain-verification-in-ext3_get_blocks.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ext3: fix chain verification in ext3_get_blocks() From: Jan Kara <jack@suse.cz> Chain verification in ext3_get_blocks() has been hosed since it called verify_chain(chain, NULL) which always returns success. As a result readers could in theory race with truncate. On the other hand the race probably cannot happen with the current locking scheme, since by the time ext3_truncate() is called all the pages are already removed and hence get_block() shouldn't be called on such pages... Signed-off-by: Jan Kara <jack@suse.cz> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- fs/ext3/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)