Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix shift-out-of-bounds due to too large exponent of block size If field s_log_block_size of superblock data is corrupted and too large, init_nilfs() and load_nilfs() still can trigger a shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn is set): shift exponent 38973 is too large for 32-bit type 'int' Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 ubsan_epilogue+0xb/0x50 __ubsan_handle_shift_out_of_bounds.cold.12+0x17b/0x1f5 init_nilfs.cold.11+0x18/0x1d [nilfs2] nilfs_mount+0x9b5/0x12b0 [nilfs2] ... This fixes the issue by adding and using a new helper function for getting block size with sanity check.

References 5

• git.kernel.org https://git.kernel.org/stable/c/8b6ef451b5701b37d9a5905534595776a662edfc
• git.kernel.org https://git.kernel.org/stable/c/a16731fa1b96226c75bbf18e73513b14fc318360
• git.kernel.org https://git.kernel.org/stable/c/ddb6615a168f97b91175e00eda4c644741cf531c
• git.kernel.org https://git.kernel.org/stable/c/ebeccaaef67a4895d2496ab8d9c2fb8d89201211
• git.kernel.org https://git.kernel.org/stable/c/ec93b5430ec0f60877a5388bb023d60624f9ab9f

Remediation