OpenCloudOS-Kernel/fs/fscache
Baokun Li e0d724932a fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF
commit 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f upstream.

The fscache_cookie_lru_timer is initialized when the fscache module
is inserted, but is not deleted when the fscache module is removed.
If timer_reduce() is called before removing the fscache module,
the fscache_cookie_lru_timer will be added to the timer list of
the current cpu. Afterwards, a use-after-free will be triggered
in the softIRQ after removing the fscache module, as follows:

==================================================================
BUG: unable to handle page fault for address: fffffbfff803c9e9
 PF: supervisor read access in kernel mode
 PF: error_code(0x0000) - not-present page
PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855
Tainted: [W]=WARN
RIP: 0010:__run_timer_base.part.0+0x254/0x8a0
Call Trace:
 <IRQ>
 tmigr_handle_remote_up+0x627/0x810
 __walk_groups.isra.0+0x47/0x140
 tmigr_handle_remote+0x1fa/0x2f0
 handle_softirqs+0x180/0x590
 irq_exit_rcu+0x84/0xb0
 sysvec_apic_timer_interrupt+0x6e/0x90
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
 default_idle_call+0x38/0x60
 do_idle+0x2b5/0x300
 cpu_startup_entry+0x54/0x60
 start_secondary+0x20d/0x280
 common_startup_64+0x13e/0x148
 </TASK>
Modules linked in: [last unloaded: netfs]
==================================================================

Therefore delete fscache_cookie_lru_timer when removing the fscahe module.

Fixes: 12bb21a29c ("fscache: Implement cookie user counting and resource pinning")
Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-12 11:11:27 +02:00
..
Kconfig fscache: remove FSCACHE_OLD_API Kconfig option 2022-04-08 23:54:37 +01:00
Makefile fscache: Provide a means to begin an operation 2022-01-07 09:22:19 +00:00
cache.c netfs, fscache: Prevent Oops in fscache_put_cache() 2024-01-31 16:19:01 -08:00
cookie.c fs/netfs/fscache_cookie: add missing "n_accesses" check 2024-08-29 17:33:15 +02:00
internal.h netfs, fscache: export fscache_put_volume() and add fscache_try_get_volume() 2024-07-25 09:50:57 +02:00
io.c use less confusing names for iov_iter direction initializers 2022-11-25 13:01:55 -05:00
main.c fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF 2024-09-12 11:11:27 +02:00
proc.c fscache: Implement cookie registration 2022-01-07 09:22:19 +00:00
stats.c fscache, cachefiles: Display stat of culling events 2022-01-07 13:43:18 +00:00
volume.c netfs, fscache: export fscache_put_volume() and add fscache_try_get_volume() 2024-07-25 09:50:57 +02:00