CVE-2023-53587

Summary

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

ring-buffer: Sync IRQ works before buffer destruction

If something was written to the buffer just before destruction, it may be possible (maybe not in a real system, but it did happen in ARCH=um with time-travel) to destroy the ringbuffer before the IRQ work ran, leading this KASAN report (or a crash without KASAN):

BUG: KASAN: slab-use-after-free in irq_work_run_list+0x11a/0x13a
Read of size 8 at addr 000000006d640a48 by task swapper/0

CPU: 0 PID: 0 Comm: swapper Tainted: G        W  O       6.3.0-rc1 #7
Stack:
 60c4f20f 0c203d48 41b58ab3 60f224fc
 600477fa 60f35687 60c4f20f 601273dd
 00000008 6101eb00 6101eab0 615be548
Call Trace:
 [<60047a58>] show_stack+0x25e/0x282
 [<60c609e0>] dump_stack_lvl+0x96/0xfd
 [<60c50d4c>] print_report+0x1a7/0x5a8
 [<603078d3>] kasan_report+0xc1/0xe9
 [<60308950>] __asan_report_load8_noabort+0x1b/0x1d
 [<60232844>] irq_work_run_list+0x11a/0x13a
 [<602328b4>] irq_work_tick+0x24/0x34
 [<6017f9dc>] update_process_times+0x162/0x196
 [<6019f335>] tick_sched_handle+0x1a4/0x1c3
 [<6019fd9e>] tick_sched_timer+0x79/0x10c
 [<601812b9>] __hrtimer_run_queues.constprop.0+0x425/0x695
 [<60182913>] hrtimer_interrupt+0x16c/0x2c4
 [<600486a3>] um_timer+0x164/0x183
 [...]

Allocated by task 411:
 save_stack_trace+0x99/0xb5
 stack_trace_save+0x81/0x9b
 kasan_save_stack+0x2d/0x54
 kasan_set_track+0x34/0x3e
 kasan_save_alloc_info+0x25/0x28
 ____kasan_kmalloc+0x8b/0x97
 __kasan_kmalloc+0x10/0x12
 __kmalloc+0xb2/0xe8
 load_elf_phdrs+0xee/0x182
 [...]

The buggy address belongs to the object at 000000006d640800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 584 bytes inside of
 freed 1024-byte region [000000006d640800, 000000006d640c00)

Add the appropriate irq_work_sync() so the work finishes before the buffers are destroyed.

Prior to the commit in the Fixes tag below, there was only a single global IRQ work, so this issue didn't exist.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/372c5ee537b8366b64b691ba29e9335525e1655e
• https://git.kernel.org/stable/c/2702b67f59d455072a08dc40312f9b090d4dec04
• https://git.kernel.org/stable/c/2399b1fda025e939b6fb1ac94505bcf718534e65
• https://git.kernel.org/stable/c/1c99f65d6af2a454bfd5207b4f6a97c8474a1191
• https://git.kernel.org/stable/c/c63741e872fcfb10e153517750f7908f0c00f60d
• https://git.kernel.org/stable/c/d9834abd8b24d1fe8092859e436fe1e0fd467c61
• https://git.kernel.org/stable/c/fc6858b7f8e1221f62ce8c6ff8a13a349c32cd76
• https://git.kernel.org/stable/c/0a65165bd24ee9231191597b7c232376fcd70cdb
• https://git.kernel.org/stable/c/675751bb20634f981498c7d66161584080cc061e

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