CVE-2024-36882

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

mm: use memalloc_nofs_save() in page_cache_ra_order()

See commit f2c817bed58d (mm: use memalloc_nofs_save in readahead path), ensure that page_cache_ra_order() do not attempt to reclaim file-backed pages too, or it leads to a deadlock, found issue when test ext4 large folio.

INFO: task DataXceiver for:7494 blocked for more than 120 seconds. echo 0 > /proc/sys/kernel/hung_task_timeout_secs disables this message. task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200 Call trace: __switch_to+0x14c/0x240 __schedule+0x82c/0xdd0 schedule+0x58/0xf0 io_schedule+0x24/0xa0 __folio_lock+0x130/0x300 migrate_pages_batch+0x378/0x918 migrate_pages+0x350/0x700 compact_zone+0x63c/0xb38 compact_zone_order+0xc0/0x118 try_to_compact_pages+0xb0/0x280 __alloc_pages_direct_compact+0x98/0x248 __alloc_pages+0x510/0x1110 alloc_pages+0x9c/0x130 folio_alloc+0x20/0x78 filemap_alloc_folio+0x8c/0x1b0 page_cache_ra_order+0x174/0x308 ondemand_readahead+0x1c8/0x2b8 page_cache_async_ra+0x68/0xb8 filemap_readahead.isra.0+0x64/0xa8 filemap_get_pages+0x3fc/0x5b0 filemap_splice_read+0xf4/0x280 ext4_file_splice_read+0x2c/0x48 [ext4] vfs_splice_read.part.0+0xa8/0x118 splice_direct_to_actor+0xbc/0x288 do_splice_direct+0x9c/0x108 do_sendfile+0x328/0x468 __arm64_sys_sendfile64+0x8c/0x148 invoke_syscall+0x4c/0x118 el0_svc_common.constprop.0+0xc8/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x4c/0x1f8 el0t_64_sync_handler+0xc0/0xc8 el0t_64_sync+0x188/0x190

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/30153e4466647a17eebfced13eede5cbe4290e69
• https://git.kernel.org/stable/c/468971c3f4b8187f25334503b68050a0e1370147
• https://git.kernel.org/stable/c/7629ef6dda1564098aadeef38e5fbd11ee8627c4
• https://git.kernel.org/stable/c/cf6a1d16c6df3c30b03f0c6a92a2ba7f86dffb45
• https://git.kernel.org/stable/c/30153e4466647a17eebfced13eede5cbe4290e69
• https://git.kernel.org/stable/c/468971c3f4b8187f25334503b68050a0e1370147
• https://git.kernel.org/stable/c/7629ef6dda1564098aadeef38e5fbd11ee8627c4
• https://git.kernel.org/stable/c/cf6a1d16c6df3c30b03f0c6a92a2ba7f86dffb45