CVE-2025-38218

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on sit_bitmap_size w/ below testcase, resize will generate a corrupted image which contains inconsistent metadata, so when mounting such image, it will trigger kernel panic: touch img truncate -s $((512*1024*1024*1024)) img mkfs.f2fs -f img $((256*1024*1024)) resize.f2fs -s -i img -t $((1024*1024*1024)) mount img /mnt/f2fs ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.h:863! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 11 UID: 0 PID: 3922 Comm: mount Not tainted 6.15.0-rc1+ #191 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:f2fs_ra_meta_pages+0x47c/0x490 Call Trace: f2fs_build_segment_manager+0x11c3/0x2600 f2fs_fill_super+0xe97/0x2840 mount_bdev+0xf4/0x140 legacy_get_tree+0x2b/0x50 vfs_get_tree+0x29/0xd0 path_mount+0x487/0xaf0 __x64_sys_mount+0x116/0x150 do_syscall_64+0x82/0x190 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fdbfde1bcfe The reaseon is: sit_i->bitmap_size is 192, so size of sit bitmap is 192*8=1536, at maximum there are 1536 sit blocks, however MAIN_SEGS is 261893, so that sit_blk_cnt is 4762, build_sit_entries() -> current_sit_addr() tries to access out-of-boundary in sit_bitmap at offset from [1536, 4762), once sit_bitmap and sit_bitmap_mirror is not the same, it will trigger f2fs_bug_on(). Let's add sanity check in f2fs_sanity_check_ckpt() to avoid panic.

Reserved 2025-04-16 | Published 2025-07-04 | Updated 2025-07-04 | Assigner Linux

Product status

Default status
unaffected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 82f51bff393e4c12cf4de553120ca831cfa4ef19
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 38ef48a8afef8df646b6f6ae7abb872f18b533c1
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before ad862f71016ba38039df1c96ed55c0a4314cc183
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 79ef8a6c4ec53d327580fd7d2b522cf4f1d05b0c
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before ee1b421c469876544e297ec1090574bd76100247
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3e5ac62a56a24f4d88ce8ffd7bc452428b235868
affected

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 5db0d252c64e91ba1929c70112352e85dc5751e7
affected

Default status
affected

5.10.239
unaffected

5.15.186
unaffected

6.1.142
unaffected

6.6.95
unaffected

6.12.35
unaffected

6.15.4
unaffected

6.16-rc1
unaffected

References

git.kernel.org/...c/82f51bff393e4c12cf4de553120ca831cfa4ef19

git.kernel.org/...c/38ef48a8afef8df646b6f6ae7abb872f18b533c1

git.kernel.org/...c/ad862f71016ba38039df1c96ed55c0a4314cc183

git.kernel.org/...c/79ef8a6c4ec53d327580fd7d2b522cf4f1d05b0c

git.kernel.org/...c/ee1b421c469876544e297ec1090574bd76100247

git.kernel.org/...c/3e5ac62a56a24f4d88ce8ffd7bc452428b235868

git.kernel.org/...c/5db0d252c64e91ba1929c70112352e85dc5751e7

cve.org (CVE-2025-38218)

nvd.nist.gov (CVE-2025-38218)

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