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| author | Baokun Li <libaokun1@huawei.com> | 2024-08-26 14:20:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 12:11:27 +0300 |
| commit | e0d724932ad12e3528f4ce97fc0f6078d0cce4bc (patch) | |
| tree | 49475beda341243cff0fc10fb90f9ed782c9b124 /fs/fscache | |
| parent | 3c6b4bcf37845c9359aed926324bed66bdd2448d (diff) | |
| download | linux-e0d724932ad12e3528f4ce97fc0f6078d0cce4bc.tar.xz | |
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: 12bb21a29c19 ("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>
Diffstat (limited to 'fs/fscache')
| -rw-r--r-- | fs/fscache/main.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/fscache/main.c b/fs/fscache/main.c index dad85fd84f6f..7a60cd96e87e 100644 --- a/fs/fscache/main.c +++ b/fs/fscache/main.c @@ -114,6 +114,7 @@ static void __exit fscache_exit(void) kmem_cache_destroy(fscache_cookie_jar); fscache_proc_cleanup(); + timer_shutdown_sync(&fscache_cookie_lru_timer); destroy_workqueue(fscache_wq); pr_notice("Unloaded\n"); } |