CVE-2024-56701

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> powerpc/pseries: Fix dtl_access_lock to be a rw_semaphore<br /> <br /> The dtl_access_lock needs to be a rw_sempahore, a sleeping lock, because<br /> the code calls kmalloc() while holding it, which can sleep:<br /> <br /> # echo 1 &gt; /proc/powerpc/vcpudispatch_stats<br /> BUG: sleeping function called from invalid context at include/linux/sched/mm.h:337<br /> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 199, name: sh<br /> preempt_count: 1, expected: 0<br /> 3 locks held by sh/199:<br /> #0: c00000000a0743f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x324/0x438<br /> #1: c0000000028c7058 (dtl_enable_mutex){+.+.}-{3:3}, at: vcpudispatch_stats_write+0xd4/0x5f4<br /> #2: c0000000028c70b8 (dtl_access_lock){+.+.}-{2:2}, at: vcpudispatch_stats_write+0x220/0x5f4<br /> CPU: 0 PID: 199 Comm: sh Not tainted 6.10.0-rc4 #152<br /> Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries<br /> Call Trace:<br /> dump_stack_lvl+0x130/0x148 (unreliable)<br /> __might_resched+0x174/0x410<br /> kmem_cache_alloc_noprof+0x340/0x3d0<br /> alloc_dtl_buffers+0x124/0x1ac<br /> vcpudispatch_stats_write+0x2a8/0x5f4<br /> proc_reg_write+0xf4/0x150<br /> vfs_write+0xfc/0x438<br /> ksys_write+0x88/0x148<br /> system_call_exception+0x1c4/0x5a0<br /> system_call_common+0xf4/0x258