CVE-2024-39474

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL<br /> <br /> commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc")<br /> includes support for __GFP_NOFAIL, but it presents a conflict with commit<br /> dd544141b9eb ("vmalloc: back off when the current task is OOM-killed"). A<br /> possible scenario is as follows:<br /> <br /> process-a<br /> __vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL)<br /> __vmalloc_area_node()<br /> vm_area_alloc_pages()<br /> --&gt; oom-killer send SIGKILL to process-a<br /> if (fatal_signal_pending(current)) break;<br /> --&gt; return NULL;<br /> <br /> To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages()<br /> if __GFP_NOFAIL set.<br /> <br /> This issue occurred during OPLUS KASAN TEST. Below is part of the log<br /> -&gt; oom-killer sends signal to process<br /> [65731.222840] [ T1308] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/apps/uid_10198,task=gs.intelligence,pid=32454,uid=10198<br /> <br /> [65731.259685] [T32454] Call trace:<br /> [65731.259698] [T32454] dump_backtrace+0xf4/0x118<br /> [65731.259734] [T32454] show_stack+0x18/0x24<br /> [65731.259756] [T32454] dump_stack_lvl+0x60/0x7c<br /> [65731.259781] [T32454] dump_stack+0x18/0x38<br /> [65731.259800] [T32454] mrdump_common_die+0x250/0x39c [mrdump]<br /> [65731.259936] [T32454] ipanic_die+0x20/0x34 [mrdump]<br /> [65731.260019] [T32454] atomic_notifier_call_chain+0xb4/0xfc<br /> [65731.260047] [T32454] notify_die+0x114/0x198<br /> [65731.260073] [T32454] die+0xf4/0x5b4<br /> [65731.260098] [T32454] die_kernel_fault+0x80/0x98<br /> [65731.260124] [T32454] __do_kernel_fault+0x160/0x2a8<br /> [65731.260146] [T32454] do_bad_area+0x68/0x148<br /> [65731.260174] [T32454] do_mem_abort+0x151c/0x1b34<br /> [65731.260204] [T32454] el1_abort+0x3c/0x5c<br /> [65731.260227] [T32454] el1h_64_sync_handler+0x54/0x90<br /> [65731.260248] [T32454] el1h_64_sync+0x68/0x6c<br /> <br /> [65731.260269] [T32454] z_erofs_decompress_queue+0x7f0/0x2258<br /> --&gt; be-&gt;decompressed_pages = kvcalloc(be-&gt;nr_pages, sizeof(struct page *), GFP_KERNEL | __GFP_NOFAIL);<br /> kernel panic by NULL pointer dereference.<br /> erofs assume kvmalloc with __GFP_NOFAIL never return NULL.<br /> [65731.260293] [T32454] z_erofs_runqueue+0xf30/0x104c<br /> [65731.260314] [T32454] z_erofs_readahead+0x4f0/0x968<br /> [65731.260339] [T32454] read_pages+0x170/0xadc<br /> [65731.260364] [T32454] page_cache_ra_unbounded+0x874/0xf30<br /> [65731.260388] [T32454] page_cache_ra_order+0x24c/0x714<br /> [65731.260411] [T32454] filemap_fault+0xbf0/0x1a74<br /> [65731.260437] [T32454] __do_fault+0xd0/0x33c<br /> [65731.260462] [T32454] handle_mm_fault+0xf74/0x3fe0<br /> [65731.260486] [T32454] do_mem_abort+0x54c/0x1b34<br /> [65731.260509] [T32454] el0_da+0x44/0x94<br /> [65731.260531] [T32454] el0t_64_sync_handler+0x98/0xb4<br /> [65731.260553] [T32454] el0t_64_sync+0x198/0x19c