CVE-2022-49363

CVE-2022-49363 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on block address in f2fs_do_zero_range() As Yanming reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215894 I have encountered a bug in F2FS file system in kernel v5.17. I have uploaded the system call sequence as case.c, and a fuzzed image can be found in google net disk The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can reproduce the bug by running the following commands: kernel BUG at fs/f2fs/segment.c:2291! Call Trace: f2fs_invalidate_blocks+0x193/0x2d0 f2fs_fallocate+0x2593/0x4a70 vfs_fallocate+0x2a5/0xac0 ksys_fallocate+0x35/0x70 __x64_sys_fallocate+0x8e/0xf0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is, after image was fuzzed, block mapping info in inode will be inconsistent with SIT table, so in f2fs_fallocate(), it will cause panic when updating SIT with invalid blkaddr. Let's fix the issue by adding sanity check on block address before updating SIT table with it.. EPSS estimates a 0.24% chance of exploitation in the next 30 days.