CVE-2024-40901: scsi: mpt3sas: Avoid test/set_bit() operating in non-allocated memory

In the Linux kernel, the following vulnerability has been resolved:

scsi: mpt3sas: Avoid test/setbit() operating in non-allocated memory

There is a potential out-of-bounds access when using testbit() on a single word. The testbit() and setbit() functions operate on long values, and when testing or setting a single word, they can exceed the word boundary. KASAN detects this issue and produces a dump:

BUG: KASAN: slab-out-of-bounds in scsihadddevice.constprop.0 (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 drivers/scsi/mpt3sas/mpt3sasscsih.c:7331) mpt3sas

Write of size 8 at addr ffff8881d26e3c60 by task kworker/u1536:2/2965

For full log, please look at [1].

Make the allocation at least the size of sizeof(unsigned long) so that setbit() and testbit() have sufficient room for read/write operations without overwriting unallocated memory.

[1] Link: https://lore.kernel.org/all/ZkNcALr3W3KGYYJG@gmail.com/

— NVD

Linux Kernel is vulnerable to a denial of service, caused by out-of-bounds access when using testbit() in mpt3sasbase.c. A local authenticated attacker could exploit this vulnerability to cause a denial of service.

— IBM