WARNING in nilfs_dat_commit_end
syzbot
syzbotHello,
syzbot found the following issue on:
HEAD commit: c3e0e1e23c70 Merge tag 'irq_urgent_for_v6.0' of git://git... git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=10f98c04880000 kernel config: https://syzkaller.appspot.com/x/.config?x=ba0d23aa7e1ffaf5 dashboard link: https://syzkaller.appspot.com/bug?extid=cbff7a52b6f99059e67f compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d224b8880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13d3e4d0880000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e7f1f925f94e/disk-c3e0e1e2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/830dabeedf0d/vmlinux-c3e0e1e2.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
------------[ cut here ]------------ WARNING: CPU: 0 PID: 3609 at fs/nilfs2/dat.c:186 nilfs_dat_commit_end+0x56b/0x610 Modules linked in: CPU: 0 PID: 3609 Comm: segctord Not tainted 6.0.0-rc7-syzkaller-00081-gc3e0e1e23c70 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:nilfs_dat_commit_end+0x56b/0x610 fs/nilfs2/dat.c:186 Code: 48 89 ee 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d e9 69 77 03 00 e8 14 49 40 fe e8 0f 46 b9 fd e9 24 fd ff ff e8 05 49 40 fe <0f> 0b e9 75 fc ff ff e8 f9 48 40 fe e8 f4 45 b9 fd 43 80 7c 25 00 RSP: 0018:ffffc9000389f2a8 EFLAGS: 00010293 RAX: ffffffff8347407b RBX: ffff888079c311a0 RCX: ffff8880775a9d80 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 000023d50af30002 RBP: 0000000000000003 R08: ffffffff83473ce9 R09: ffffed100f211f9b R10: ffffed100f211f9b R11: 1ffff1100f211f9a R12: ffff8880723fda40 R13: ffffc9000389f3b8 R14: ffff888074fb8180 R15: 000023d50af30002 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fec40ab81d0 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> nilfs_dat_commit_update+0x25/0x40 fs/nilfs2/dat.c:236 nilfs_direct_propagate+0x215/0x390 fs/nilfs2/direct.c:277 nilfs_bmap_propagate+0x6d/0x120 fs/nilfs2/bmap.c:337 nilfs_collect_file_data+0x49/0xc0 fs/nilfs2/segment.c:568 nilfs_segctor_apply_buffers+0x192/0x380 fs/nilfs2/segment.c:1012 nilfs_segctor_scan_file+0x842/0xaf0 fs/nilfs2/segment.c:1061 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1170 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1497 [inline] nilfs_segctor_do_construct+0x1cce/0x6fe0 fs/nilfs2/segment.c:2039 nilfs_segctor_construct+0x143/0x8d0 fs/nilfs2/segment.c:2375 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2483 [inline] nilfs_segctor_thread+0x534/0x1180 fs/nilfs2/segment.c:2566 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller-/JYPxA39Uh5TLH3MbocFF+G/[email protected]
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
Ryusuke Konishi
maintainerPATCH 1/1 nilfs2: prevent WARNING in nilfs_dat_commit_end()
If nilfs2 reads a corrupted disk image and its DAT metadata file contains invalid lifetime data for a virtual block number, a kernel warning can be generated by the WARN_ON check in nilfs_dat_commit_end() and can panic if the kernel is booted with panic_on_warn.
This patch avoids the issue with a sanity check that treats it as an error.
Since error return is not allowed in the execution phase of nilfs_dat_commit_end(), this inserts that sanity check in nilfs_dat_prepare_end(), which prepares for nilfs_dat_commit_end().
As the error code, -EINVAL is returned to notify bmap layer of the metadata corruption. When the bmap layer sees this code, it handles the abnormal situation and replaces the return code with -EIO as it should.
---
Andrew, please add this patch to the queue. This fixes another WARN_ON hit in fs/nilfs2/dat.c for a corrupted disk image pattern.
Thanks,
Ryusuke Konishi
fs/nilfs2/dat.c | 11 +++++++++++
1 file changed, 11 insertions(+)
fs/nilfs2/dat.c +11 -0
@@ -158,6 +158,7 @@ void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,int nilfs_dat_prepare_end (struct inode *dat,struct nilfs_palloc_req *req) {struct nilfs_dat_entry *entry; +__u64 start;sector_t blocknr;void *kaddr;int ret;
@@ -169,6 +170,7 @@ int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req) kaddr =kmap_atomic (req->pr_entry_bh->b_page); entry =nilfs_palloc_block_get_entry (dat, req->pr_entry_nr, req->pr_entry_bh, kaddr); + start =le64_to_cpu (entry->de_start); blocknr =le64_to_cpu (entry->de_blocknr);kunmap_atomic (kaddr);
@@ -179,6 +181,15 @@ int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)return ret; } } +if (unlikely (start >nilfs_mdt_cno (dat))) { +nilfs_err (dat->i_sb, +"vblocknr = %llu has abnormal lifetime: start cno (= %llu) > current cno (= %llu)" , + (unsigned long long )req->pr_entry_nr, + (unsigned long long )start, + (unsigned long long )nilfs_mdt_cno (dat)); +nilfs_dat_abort_entry (dat, req); +return -EINVAL ; + }return 0 ; }
Signature · 1 line
2.34.1