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author | Zheng Yejian <zhengyejian1@huawei.com> | 2024-04-10 04:58:02 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-17 12:19:34 +0300 |
commit | d15023fb407337028a654237d8968fefdcf87c2f (patch) | |
tree | 07110137da36930448b85c8fd6b9d6a190e8925f /drivers | |
parent | 96b7b0934a343c80425bb01705a1f9ea0f029961 (diff) | |
download | linux-d15023fb407337028a654237d8968fefdcf87c2f.tar.xz |
kprobes: Fix possible use-after-free issue on kprobe registration
commit 325f3fb551f8cd672dbbfc4cf58b14f9ee3fc9e8 upstream.
When unloading a module, its state is changing MODULE_STATE_LIVE ->
MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take
a time. `is_module_text_address()` and `__module_text_address()`
works with MODULE_STATE_LIVE and MODULE_STATE_GOING.
If we use `is_module_text_address()` and `__module_text_address()`
separately, there is a chance that the first one is succeeded but the
next one is failed because module->state becomes MODULE_STATE_UNFORMED
between those operations.
In `check_kprobe_address_safe()`, if the second `__module_text_address()`
is failed, that is ignored because it expected a kernel_text address.
But it may have failed simply because module->state has been changed
to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify
non-exist module text address (use-after-free).
To fix this problem, we should not use separated `is_module_text_address()`
and `__module_text_address()`, but use only `__module_text_address()`
once and do `try_module_get(module)` which is only available with
MODULE_STATE_LIVE.
Link: https://lore.kernel.org/all/20240410015802.265220-1-zhengyejian1@huawei.com/
Fixes: 28f6c37a2910 ("kprobes: Forbid probing on trampoline and BPF code areas")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions