From: Chao Yu Date: Fri, 22 May 2026 07:53:29 +0000 (+0800) Subject: f2fs: fix to do sanity check on f2fs_get_node_folio_ra() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8712353ed80f87271d732297567dcdbe4b84e8c7;p=thirdparty%2Flinux.git f2fs: fix to do sanity check on f2fs_get_node_folio_ra() kernel BUG at fs/f2fs/file.c:845! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:f2fs_do_truncate_blocks+0x1115/0x1140 fs/f2fs/file.c:845 Code: fc fc 90 0f 0b e8 8b 9d 9a fd 90 0f 0b e8 83 9d 9a fd 48 89 df 48 c7 c6 60 d1 1a 8c e8 54 f1 fc fc 90 0f 0b e8 6c 9d 9a fd 90 <0f> 0b e8 64 9d 9a fd 90 0f 0b 90 e9 93 fd ff ff e8 56 9d 9a fd 90 RSP: 0018:ffffc9000e4474c0 EFLAGS: 00010283 RAX: ffffffff842b1d34 RBX: 0000000000000003 RCX: 0000000000100000 RDX: ffffc9000f03a000 RSI: 0000000000035503 RDI: 0000000000035504 RBP: ffffc9000e447608 R08: ffff8880123b0000 R09: 0000000000000002 R10: 00000000fffffffe R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000000 R14: 1ffff92001c88ea0 R15: 00000000ffff039c FS: 00007f7e02ee36c0(0000) GS:ffff88808c887000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff0305c4000 CR3: 0000000012d4c000 CR4: 0000000000352ef0 Call Trace: f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:882 f2fs_truncate+0x471/0x7c0 fs/f2fs/file.c:940 f2fs_evict_inode+0xa3f/0x1ac0 fs/f2fs/inode.c:907 evict+0x61e/0xb10 fs/inode.c:841 f2fs_fill_super+0x5f43/0x78f0 fs/f2fs/super.c:5224 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f count = ADDRS_PER_PAGE(dn.node_folio, inode); count -= dn.ofs_in_node; f2fs_bug_on(sbi, count < 0); The fuzz test will trigger above bug_on in f2fs. The root cause should be: in the corrupted inode, there is a direct node which has the same ino and nid in its footer, so in f2fs_do_truncate_blocks(), after f2fs_get_dnode_of_data() finds such dnode: 1) ADDRS_PER_PAGE(dn.node_folio, inode) will return 923 2) once dn.ofs_in_node points to addr[923, 1017] Then it will trigger the system panic. Let's introduce NODE_TYPE_NON_IXNODE to indicate current node should not be an inode or xattr node, and then use it in below path to detect inconsistent node chain in inode mapping table: - f2fs_do_truncate_blocks - f2fs_get_dnode_of_data - f2fs_get_node_folio_ra - __get_node_folio - f2fs_sanity_check_node_footer - case NODE_TYPE_NON_IXNODE -> check whether it is inode|xnode Cc: stable@kernel.org Reported-by: syzbot+2488d8d751b27f7ce268@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69fa3697.170a0220.59368.0018.GAE@google.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9f24287de4c31..086bc52439794 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1592,6 +1592,7 @@ enum node_type { NODE_TYPE_INODE, NODE_TYPE_XATTR, NODE_TYPE_NON_INODE, + NODE_TYPE_NON_IXNODE, /* non inode and xnode */ }; /* a threshold of maximum elapsed time in critical region to print tracepoint */ diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index cd5a394f61114..38917e4a73194 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1548,6 +1548,10 @@ int f2fs_sanity_check_node_footer(struct f2fs_sb_info *sbi, if (is_inode) goto out_err; break; + case NODE_TYPE_NON_IXNODE: + if (is_inode || is_xnode) + goto out_err; + break; default: break; } @@ -1643,7 +1647,7 @@ static struct folio *f2fs_get_node_folio_ra(struct folio *parent, int start) struct f2fs_sb_info *sbi = F2FS_F_SB(parent); nid_t nid = get_nid(parent, start, false); - return __get_node_folio(sbi, nid, parent, start, NODE_TYPE_REGULAR); + return __get_node_folio(sbi, nid, parent, start, NODE_TYPE_NON_IXNODE); } static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)