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 by taking min value from the actual exponent and maximum possible number of bits.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
bec02dbbafad534674309f8b948094900f456797 to < 1f61d509257d6a05763d05bf37943b35306522b1affectedbec02dbbafad534674309f8b948094900f456797 to < f4ef9bef023d5c543cb0f3194ecacfd47ef590ecaffectedbec02dbbafad534674309f8b948094900f456797 to < 59121bb38fdc01434ea3fe361ee02b59f036227faffectedbec02dbbafad534674309f8b948094900f456797 to < 1ab2cfe19700fb3dde4c7dfec392acff34db3120affectedbec02dbbafad534674309f8b948094900f456797 to < 1b120f151871eb47ce9f283c007af3f8ae1d990eaffectedbec02dbbafad534674309f8b948094900f456797 to < 364022095bdd4108efdaaa68576afa4712a5d085affectedbec02dbbafad534674309f8b948094900f456797 to < 9bce8005ec0dcb23a58300e8522fe4a31da606faaffected
Linux Linux
Default version status: affected
5.10affected0 to < 5.10unaffected5.10.227 to ≤ 5.10.*unaffected5.15.168 to ≤ 5.15.*unaffected6.1.113 to ≤ 6.1.*unaffected6.6.55 to ≤ 6.6.*unaffected6.10.14 to ≤ 6.10.*unaffected6.11.3 to ≤ 6.11.*unaffected6.12 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/1f61d509257d6a05763d05bf37943b35306522b1 ↗
- https://git.kernel.org/stable/c/f4ef9bef023d5c543cb0f3194ecacfd47ef590ec ↗
- https://git.kernel.org/stable/c/59121bb38fdc01434ea3fe361ee02b59f036227f ↗
- https://git.kernel.org/stable/c/1ab2cfe19700fb3dde4c7dfec392acff34db3120 ↗
- https://git.kernel.org/stable/c/1b120f151871eb47ce9f283c007af3f8ae1d990e ↗
- https://git.kernel.org/stable/c/364022095bdd4108efdaaa68576afa4712a5d085 ↗
- https://git.kernel.org/stable/c/9bce8005ec0dcb23a58300e8522fe4a31da606fa ↗
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html ↗
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html ↗