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().
git.kernel.org/linus/3ab0598e6d860ef49d029943ba80f627c15c15d6 (5.13-rc1)
git.kernel.org/stable/c/1c20a4896409f5ca1c770e1880c33d0a28a8b10f
git.kernel.org/stable/c/3ab0598e6d860ef49d029943ba80f627c15c15d6
git.kernel.org/stable/c/822054e5026c43b1dd60cf387dd999e95ee2ecc2
git.kernel.org/stable/c/860afd680d9cc1dabd61cda3cd246f60aa1eb705
launchpad.net/bugs/cve/CVE-2021-47007
nvd.nist.gov/vuln/detail/CVE-2021-47007
security-tracker.debian.org/tracker/CVE-2021-47007
www.cve.org/CVERecord?id=CVE-2021-47007