2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: "Darrick J. Wong" <[email protected]> commit e531d0bceb402e643a4499de40dd3fa39d8d2e43 upstream. The journal revoke block recovery code does not check r_count for sanity, which means that an evil value of r_count could result in the kernel reading off the end of the revoke table and into whatever garbage lies beyond. This could crash the kernel, so fix that. However, in testing this fix, I discovered that the code to write out the revoke tables also was not correctly checking to see if the block was full -- the current offset check is fine so long as the revoke table space size is a multiple of the record size, but this is not true when either journal_csum_v[23] are set. Signed-off-by: Darrick J. Wong <[email protected]> Signed-off-by: Theodore Ts'o <[email protected]> Reviewed-by: Jan Kara <[email protected]> [bwh: Backported to 3.2: journal checksumming is not supported, so only the first fix is needed] Signed-off-by: Ben Hutchings <[email protected]> (cherry picked from commit 2f6a2bcc01bc9ed73bfb4d698da94ed2a5fcb18c) Signed-off-by: Willy Tarreau <[email protected]> --- fs/jbd2/recovery.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 7306328..59cc9c5 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -718,11 +718,16 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, { jbd2_journal_revoke_header_t *header; int offset, max; + __u32 rcount; int record_len = 4; header = (jbd2_journal_revoke_header_t *) bh->b_data; offset = sizeof(jbd2_journal_revoke_header_t); - max = be32_to_cpu(header->r_count); + rcount = be32_to_cpu(header->r_count); + + if (rcount > journal->j_blocksize) + return -EINVAL; + max = rcount; if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) record_len = 8; -- 1.7.12.2.21.g234cd45.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
