From: Christoph Hellwig Date: Tue, 30 Apr 2024 04:07:55 +0000 (+0200) Subject: xfs: fix log recovery buffer allocation for the legacy h_size fixup X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=45cf976008ddef4a9c9a30310c9b4fb2a9a6602a;p=linux.git xfs: fix log recovery buffer allocation for the legacy h_size fixup Commit a70f9fe52daa ("xfs: detect and handle invalid iclog size set by mkfs") added a fixup for incorrect h_size values used for the initial umount record in old xfsprogs versions. Later commit 0c771b99d6c9 ("xfs: clean up calculation of LR header blocks") cleaned up the log reover buffer calculation, but stoped using the fixed up h_size value to size the log recovery buffer, which can lead to an out of bounds access when the incorrect h_size does not come from the old mkfs tool, but a fuzzer. Fix this by open coding xlog_logrec_hblks and taking the fixed h_size into account for this calculation. Fixes: 0c771b99d6c9 ("xfs: clean up calculation of LR header blocks") Reported-by: Sam Sun Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Reviewed-by: "Darrick J. Wong" Signed-off-by: Chandan Babu R --- diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index b445e8ce4a7d2..bb8957927c3c2 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -2999,7 +2999,7 @@ xlog_do_recovery_pass( int error = 0, h_size, h_len; int error2 = 0; int bblks, split_bblks; - int hblks, split_hblks, wrapped_hblks; + int hblks = 1, split_hblks, wrapped_hblks; int i; struct hlist_head rhash[XLOG_RHASH_SIZE]; LIST_HEAD (buffer_list); @@ -3055,14 +3055,22 @@ xlog_do_recovery_pass( if (error) goto bread_err1; - hblks = xlog_logrec_hblks(log, rhead); - if (hblks != 1) { - kvfree(hbp); - hbp = xlog_alloc_buffer(log, hblks); + /* + * This open codes xlog_logrec_hblks so that we can reuse the + * fixed up h_size value calculated above. Without that we'd + * still allocate the buffer based on the incorrect on-disk + * size. + */ + if (h_size > XLOG_HEADER_CYCLE_SIZE && + (rhead->h_version & cpu_to_be32(XLOG_VERSION_2))) { + hblks = DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE); + if (hblks > 1) { + kvfree(hbp); + hbp = xlog_alloc_buffer(log, hblks); + } } } else { ASSERT(log->l_sectBBsize == 1); - hblks = 1; hbp = xlog_alloc_buffer(log, 1); h_size = XLOG_BIG_RECORD_BSIZE; }