5.5

CVE-2021-47007

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().
Data is provided by the National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.8 < 5.10.38
Linux ≫ Linux Kernel Version >= 5.11 < 5.11.22
Linux ≫ Linux Kernel Version >= 5.12 < 5.12.5
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.02% 0.031
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-754 Improper Check for Unusual or Exceptional Conditions

The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.