CVEvulnerability
CVE-2021-47007
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2024-02-28
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-754
Description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix panic during f2fs_resize_fs()
f2fs_resize_fs() hangs in below callstack with testcase:
- mkfs 16GB image & mount image
- dd 8GB fileA
- dd 8GB fileB
- sync
- rm fileA
- sync
- resize filesystem to 8GB
kernel BUG at segment.c:2484!
Call Trace:
allocate_segment_by_default+0x92/0xf0 [f2fs]
f2fs_allocate_data_block+0x44b/0x7e0 [f2fs]
do_write_page+0x5a/0x110 [f2fs]
f2fs_outplace_write_data+0x55/0x100 [f2fs]
f2fs_do_write_data_page+0x392/0x850 [f2fs]
move_data_page+0x233/0x320 [f2fs]
do_garbage_collect+0x14d9/0x1660 [f2fs]
free_segment_range+0x1f7/0x310 [f2fs]
f2fs_resize_fs+0x118/0x330 [f2fs]
__f2fs_ioctl+0x487/0x3680 [f2fs]
__x64_sys_ioctl+0x8e/0xd0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The root cause is we forgot to check that whether we have enough space
in resized filesystem to store all valid blocks in before-resizing
filesystem, then allocator will run out-of-space during block migration
in free_segment_range().
Affected configurations
• linux linux kernel (>= 5.8 < 5.10.38)
• linux linux kernel (>= 5.11 < 5.11.22)
• linux linux kernel (>= 5.12 < 5.12.5)
Related
Weakness · CWE (1)
- CWE-754 Improper Check for Unusual or Exceptional Conditions weakness
References
- https://git.kernel.org/stable/c/1c20a4896409f5ca1c770e1880c33d0a28a8b10f Patch
- https://git.kernel.org/stable/c/3ab0598e6d860ef49d029943ba80f627c15c15d6 Patch
- https://git.kernel.org/stable/c/822054e5026c43b1dd60cf387dd999e95ee2ecc2 Patch
- https://git.kernel.org/stable/c/860afd680d9cc1dabd61cda3cd246f60aa1eb705 Patch
- https://git.kernel.org/stable/c/1c20a4896409f5ca1c770e1880c33d0a28a8b10f Patch
- https://git.kernel.org/stable/c/3ab0598e6d860ef49d029943ba80f627c15c15d6 Patch
- https://git.kernel.org/stable/c/822054e5026c43b1dd60cf387dd999e95ee2ecc2 Patch
- https://git.kernel.org/stable/c/860afd680d9cc1dabd61cda3cd246f60aa1eb705 Patch