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| author | Jing Xia <jing.xia@unisoc.com> | 2023-12-20 05:46:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-04 19:13:04 +0300 |
| commit | 93ec4a3b76404bce01bd5c9032bef5df6feb1d62 (patch) | |
| tree | f60922c1cf2e540d4b4647f14e1c3e076b2beeb2 /drivers/base | |
| parent | db2292b01b799e926abfdbd6fafa1f27f0d0e457 (diff) | |
| download | linux-93ec4a3b76404bce01bd5c9032bef5df6feb1d62.tar.xz | |
class: fix use-after-free in class_register()
The lock_class_key is still registered and can be found in
lock_keys_hash hlist after subsys_private is freed in error
handler path.A task who iterate over the lock_keys_hash
later may cause use-after-free.So fix that up and unregister
the lock_class_key before kfree(cp).
On our platform, a driver fails to kset_register because of
creating duplicate filename '/class/xxx'.With Kasan enabled,
it prints a invalid-access bug report.
KASAN bug report:
BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc
Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252
Pointer tag: [15], memory tag: [fe]
CPU: 7 PID: 252 Comm: modprobe Tainted: G W
6.6.0-mainline-maybe-dirty #1
Call trace:
dump_backtrace+0x1b0/0x1e4
show_stack+0x2c/0x40
dump_stack_lvl+0xac/0xe0
print_report+0x18c/0x4d8
kasan_report+0xe8/0x148
__hwasan_store8_noabort+0x88/0x98
lockdep_register_key+0x19c/0x1bc
class_register+0x94/0x1ec
init_module+0xbc/0xf48 [rfkill]
do_one_initcall+0x17c/0x72c
do_init_module+0x19c/0x3f8
...
Memory state around the buggy address:
ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a
ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe
>ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
^
ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03
As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access
not use-after-free here.In this case, modprobe is manipulating
the corrupted lock_keys_hash hlish where lock_class_key is already
freed before.
It's worth noting that this only can happen if lockdep is enabled,
which is not true for normal system.
Fixes: dcfbb67e48a2 ("driver core: class: use lock_class_key already present in struct subsys_private")
Cc: stable <stable@kernel.org>
Signed-off-by: Jing Xia <jing.xia@unisoc.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Link: https://lore.kernel.org/r/20231220024603.186078-1-jing.xia@unisoc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/class.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/base/class.c b/drivers/base/class.c index 7e78aee0fd6c..7b38fdf8e1d7 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -213,6 +213,7 @@ int class_register(const struct class *cls) return 0; err_out: + lockdep_unregister_key(key); kfree(cp); return error; } |