From c3b880acadc95d6e019eae5d669e072afda24f1b Mon Sep 17 00:00:00 2001 From: Long Li Date: Tue, 13 Jun 2023 08:49:20 -0700 Subject: [PATCH] xfs: fix ag count overflow during growfs I found a corruption during growfs: XFS (loop0): Internal error agbno >= mp->m_sb.sb_agblocks at line 3661 of file fs/xfs/libxfs/xfs_alloc.c. Caller __xfs_free_extent+0x28e/0x3c0 CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257 Call Trace: dump_stack_lvl+0x50/0x70 xfs_corruption_error+0x134/0x150 __xfs_free_extent+0x2c1/0x3c0 xfs_ag_extend_space+0x291/0x3e0 xfs_growfs_data+0xd72/0xe90 xfs_file_ioctl+0x5f9/0x14a0 __x64_sys_ioctl+0x13e/0x1c0 do_syscall_64+0x39/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd XFS (loop0): Corruption detected. Unmount and run xfs_repair XFS (loop0): Internal error xfs_trans_cancel at line 1097 of file fs/xfs/xfs_trans.c. Caller xfs_growfs_data+0x691/0xe90 CPU: 0 PID: 573 Comm: xfs_growfs Not tainted 6.3.0-rc7-next-20230420-00001-gda8c95746257 Call Trace: dump_stack_lvl+0x50/0x70 xfs_error_report+0x93/0xc0 xfs_trans_cancel+0x2c0/0x350 xfs_growfs_data+0x691/0xe90 xfs_file_ioctl+0x5f9/0x14a0 __x64_sys_ioctl+0x13e/0x1c0 do_syscall_64+0x39/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2d86706577 The bug can be reproduced with the following sequence: # truncate -s 1073741824 xfs_test.img # mkfs.xfs -f -b size=1024 -d agcount=4 xfs_test.img # truncate -s 2305843009213693952 xfs_test.img # mount -o loop xfs_test.img /mnt/test # xfs_growfs -D 1125899907891200 /mnt/test The root cause is that during growfs, user space passed in a large value of newblcoks to xfs_growfs_data_private(), due to current sb_agblocks is too small, new AG count will exceed UINT_MAX. Because of AG number type is unsigned int and it would overflow, that caused nagcount much smaller than the actual value. During AG extent space, delta blocks in xfs_resizefs_init_new_ags() will much larger than the actual value due to incorrect nagcount, even exceed UINT_MAX. This will cause corruption and be detected in __xfs_free_extent. Fix it by growing the filesystem to up to the maximally allowed AGs and not return EINVAL when new AG count overflow. Signed-off-by: Long Li Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_fs.h | 2 ++ fs/xfs/xfs_fsops.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index 1cfd5bc..9c60ebb 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -257,6 +257,8 @@ typedef struct xfs_fsop_resblks { #define XFS_MAX_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_BLOCKSIZE) #define XFS_MAX_CRC_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_CRC_BLOCKSIZE) +#define XFS_MAX_AGNUMBER ((xfs_agnumber_t)(NULLAGNUMBER - 1)) + /* keep the maximum size under 2^31 by a small amount */ #define XFS_MAX_LOG_BYTES \ ((2 * 1024 * 1024 * 1024ULL) - XFS_MIN_LOG_BYTES) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 5f00527..839ca9a 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -115,11 +115,16 @@ xfs_growfs_data_private( nb_div = nb; nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks); - nagcount = nb_div + (nb_mod != 0); - if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) { - nagcount--; - nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks; + if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS) + nb_div++; + else if (nb_mod) + nb = nb_div * mp->m_sb.sb_agblocks; + + if (nb_div > XFS_MAX_AGNUMBER + 1) { + nb_div = XFS_MAX_AGNUMBER + 1; + nb = nb_div * mp->m_sb.sb_agblocks; } + nagcount = nb_div; delta = nb - mp->m_sb.sb_dblocks; /* * Reject filesystems with a single AG because they are not -- 2.7.4