Wind River Support Network

Description

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

CREATE(Triage):(User=admin) [CVE-2025-38218 (https://nvd.nist.gov/vuln/detail/CVE-2025-38218)