linux-stable.git/fs/f2fs/node.c, branch linux-6.17.y

f2fs: fix to detect potential corrupted nid in free_nid_list

2025-11-13T20:37:04+00:00

[ Upstream commit 8fc6056dcf79937c46c97fa4996cda65956437a9 ]

As reported, on-disk footer.ino and footer.nid is the same and
out-of-range, let's add sanity check on f2fs_alloc_nid() to detect
any potential corruption in free_nid_list.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix to do sanity check on node footer for non inode dnode

2025-10-12T11:01:57+00:00

commit c18ecd99e0c707ef8f83cace861cbc3162f4fdf1 upstream.

As syzbot reported below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/file.c:1243!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full)
RIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243
Call Trace:
 
 f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306
 f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018
 vfs_fallocate+0x666/0x7e0 fs/open.c:342
 ksys_fallocate fs/open.c:366 [inline]
 __do_sys_fallocate fs/open.c:371 [inline]
 __se_sys_fallocate fs/open.c:369 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:369
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1e65f8ebe9

w/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent
truncation range in direct node in f2fs_truncate_hole().

The root cause is: a non-inode dnode may has the same footer.ino and
footer.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE()
may return wrong blkaddr count which may be 923 typically, by chance,
dn.ofs_in_node is equal to 923, then count can be calculated to 0 in below
statement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...).

	count = min(end_offset - dn.ofs_in_node, pg_end - pg_start);

This patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing
passing the new_type to sanity_check_node_footer in f2fs_get_node_folio()
to detect corruption that a non-inode dnode has the same footer.ino and
footer.nid.

Scripts to reproduce:
mkfs.f2fs -f /dev/vdb
mount /dev/vdb /mnt/f2fs
touch /mnt/f2fs/foo
touch /mnt/f2fs/bar
dd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8
umount /mnt/f2fs
inject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb
mount /dev/vdb /mnt/f2fs
xfs_io /mnt/f2fs/foo -c "fpunch 6984k 4k"

Cc: stable@kernel.org
Reported-by: syzbot+b9c7ffd609c3f09416ab@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/68a68e27.050a0220.1a3988.0002.GAE@google.com
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Greg Kroah-Hartman

f2fs: directly add newly allocated pre-dirty nat entry to dirty set list

2025-07-28T16:30:02+00:00

When we need to alloc nat entry and set it dirty, we can directly add it to
dirty set list(or initialize its list_head for new_ne) instead of adding it
to clean list and make a move. Introduce init_dirty flag to do it.

Signed-off-by: wangzijie 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: avoid redundant clean nat entry move in lru list

2025-07-28T16:29:59+00:00

__lookup_nat_cache follows LRU manner to move clean nat entry, when nat
entries are going to be dirty, no need to move them to tail of lru list.
Introduce a parameter 'for_dirty' to avoid it.

Signed-off-by: wangzijie 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to avoid out-of-boundary access in dnode page

2025-07-22T15:58:15+00:00

As Jiaming Zhang reported:

 
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x1c1/0x2a0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x17e/0x800 mm/kasan/report.c:480
 kasan_report+0x147/0x180 mm/kasan/report.c:593
 data_blkaddr fs/f2fs/f2fs.h:3053 [inline]
 f2fs_data_blkaddr fs/f2fs/f2fs.h:3058 [inline]
 f2fs_get_dnode_of_data+0x1a09/0x1c40 fs/f2fs/node.c:855
 f2fs_reserve_block+0x53/0x310 fs/f2fs/data.c:1195
 prepare_write_begin fs/f2fs/data.c:3395 [inline]
 f2fs_write_begin+0xf39/0x2190 fs/f2fs/data.c:3594
 generic_perform_write+0x2c7/0x910 mm/filemap.c:4112
 f2fs_buffered_write_iter fs/f2fs/file.c:4988 [inline]
 f2fs_file_write_iter+0x1ec8/0x2410 fs/f2fs/file.c:5216
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x546/0xa90 fs/read_write.c:686
 ksys_write+0x149/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x3d0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The root cause is in the corrupted image, there is a dnode has the same
node id w/ its inode, so during f2fs_get_dnode_of_data(), it tries to
access block address in dnode at offset 934, however it parses the dnode
as inode node, so that get_dnode_addr() returns 360, then it tries to
access page address from 360 + 934 * 4 = 4096 w/ 4 bytes.

To fix this issue, let's add sanity check for node id of all direct nodes
during f2fs_get_dnode_of_data().

Cc: stable@kernel.org
Reported-by: Jiaming Zhang 
Closes: https://groups.google.com/g/syzkaller/c/-ZnaaOOfO3M
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Pass a folio to F2FS_NODE()

2025-07-22T15:57:48+00:00

All callers now have a folio so pass it in

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Pass the nat_blk to __update_nat_bits()

2025-07-22T15:57:44+00:00

The page argument is only used to look up the address of the nat_blk.
Since the caller already has it, pass it in instead.  Also mark it const
as the nat_blk isn't modified by this function.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Convert get_next_nat_page() to get_next_nat_folio()

2025-07-22T15:57:41+00:00

Return a folio from this function and convert its one caller.
Removes a call to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Add folio counterparts to page_private_flags functions

2025-07-22T15:57:05+00:00

Name these new functions folio_test_f2fs_*(), folio_set_f2fs_*() and
folio_clear_f2fs_*().  Convert all callers which currently have a folio
and cast back to a page.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Pass a folio to IS_INODE()

2025-07-22T15:57:02+00:00

All callers now have a folio so pass it in.  Also make it const to help
the compiler.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim