In the Linux kernel, the following vulnerability has been resolved:
drivers: perf: Check findfirstbit() return value
We must check the return value of findfirstbit() before using the return value as an index array since it happens to overflow the array and then panic:
[ 107.318430] Kernel BUG [#1] [ 107.319434] CPU: 3 PID: 1238 Comm: kill Tainted: G E 6.6.0-rc6ubuntu-defconfig #2 [ 107.319465] Hardware name: riscv-virtio,qemu (DT) [ 107.319551] epc : pmusbiovfhandler+0x3a4/0x3ae [ 107.319840] ra : pmusbiovfhandler+0x52/0x3ae [ 107.319868] epc : ffffffff80a0a77c ra : ffffffff80a0a42a sp : ffffaf83fecda350 [ 107.319884] gp : ffffffff823961a8 tp : ffffaf8083db1dc0 t0 : ffffaf83fecda480 [ 107.319899] t1 : ffffffff80cafe62 t2 : 000000000000ff00 s0 : ffffaf83fecda520 [ 107.319921] s1 : ffffaf83fecda380 a0 : 00000018fca29df0 a1 : ffffffffffffffff [ 107.319936] a2 : 0000000001073734 a3 : 0000000000000004 a4 : 0000000000000000 [ 107.319951] a5 : 0000000000000040 a6 : 000000001d1c8774 a7 : 0000000000504d55 [ 107.319965] s2 : ffffffff82451f10 s3 : ffffffff82724e70 s4 : 000000000000003f [ 107.319980] s5 : 0000000000000011 s6 : ffffaf8083db27c0 s7 : 0000000000000000 [ 107.319995] s8 : 0000000000000001 s9 : 00007fffb45d6558 s10: 00007fffb45d81a0 [ 107.320009] s11: ffffaf7ffff60000 t3 : 0000000000000004 t4 : 0000000000000000 [ 107.320023] t5 : ffffaf7f80000000 t6 : ffffaf8000000000 [ 107.320037] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 107.320081] [<ffffffff80a0a77c>] pmusbiovfhandler+0x3a4/0x3ae [ 107.320112] [<ffffffff800b42d0>] handlepercpudevidirq+0x9e/0x1a0 [ 107.320131] [<ffffffff800ad92c>] generichandledomainirq+0x28/0x36 [ 107.320148] [<ffffffff8065f9f8>] riscvintcirq+0x36/0x4e [ 107.320166] [<ffffffff80caf4a0>] handleriscvirq+0x54/0x86 [ 107.320189] [<ffffffff80cb0036>] doirq+0x64/0x96 [ 107.320271] Code: 85a6 855e b097 ff7f 80e7 9220 b709 9002 4501 bbd9 (9002) 6097 [ 107.320585] ---[ end trace 0000000000000000 ]--- [ 107.320704] Kernel panic - not syncing: Fatal exception in interrupt [ 107.320775] SMP: stopping secondary CPUs [ 107.321219] Kernel Offset: 0x0 from 0xffffffff80000000 [ 107.333051] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---