CVE-2024-49933

/// Technical description

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

blk_iocost: fix more out of bound shifts

Recently running UBSAN caught few out of bound shifts in the

ioc_forgive_debts() function:

UBSAN: shift-out-of-bounds in block/blk-iocost.c:2142:38

shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long

long')

...

UBSAN: shift-out-of-bounds in block/blk-iocost.c:2144:30

shift exponent 80 is too large for 64-bit type 'u64' (aka 'unsigned long

long')

...

Call Trace:

<IRQ>

dump_stack_lvl+0xca/0x130

__ubsan_handle_shift_out_of_bounds+0x22c/0x280

? __lock_acquire+0x6441/0x7c10

ioc_timer_fn+0x6cec/0x7750

? blk_iocost_init+0x720/0x720

? call_timer_fn+0x5d/0x470

call_timer_fn+0xfa/0x470

? blk_iocost_init+0x720/0x720

__run_timer_base+0x519/0x700

...

Actual impact of this issue was not identified but I propose to fix the

undefined behaviour.

The proposed fix to prevent those out of bound shifts consist of

precalculating exponent before using it the shift operations b

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References