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| author | Zheng Yejian <zhengyejian1@huawei.com> | 2023-03-30 10:52:23 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-04-13 16:48:24 +0200 |
| commit | 33a503b7c33937d8bfbade7b95b55c0d8095b4bf (patch) | |
| tree | bbb87ee7412d4fe530f2654db53569bb5785a380 | |
| parent | 20c5e10950e9d82ca0db41072e3a57b58536bc4a (diff) | |
| download | linux-33a503b7c33937d8bfbade7b95b55c0d8095b4bf.tar.gz linux-33a503b7c33937d8bfbade7b95b55c0d8095b4bf.tar.bz2 linux-33a503b7c33937d8bfbade7b95b55c0d8095b4bf.zip | |
ftrace: Fix issue that 'direct->addr' not restored in modify_ftrace_direct()
commit 2a2d8c51defb446e8d89a83f42f8e5cd529111e9 upstream.
Syzkaller report a WARNING: "WARN_ON(!direct)" in modify_ftrace_direct().
Root cause is 'direct->addr' was changed from 'old_addr' to 'new_addr' but
not restored if error happened on calling ftrace_modify_direct_caller().
Then it can no longer find 'direct' by that 'old_addr'.
To fix it, restore 'direct->addr' to 'old_addr' explicitly in error path.
Link: https://lore.kernel.org/linux-trace-kernel/20230330025223.1046087-1-zhengyejian1@huawei.com
Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <ast@kernel.org>
Cc: <daniel@iogearbox.net>
Fixes: 8a141dd7f706 ("ftrace: Fix modify_ftrace_direct.")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/ftrace.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a3a15fe90e0a..06927f772d50 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5383,12 +5383,15 @@ int modify_ftrace_direct(unsigned long ip, ret = 0; } - if (unlikely(ret && new_direct)) { - direct->count++; - list_del_rcu(&new_direct->next); - synchronize_rcu_tasks(); - kfree(new_direct); - ftrace_direct_func_count--; + if (ret) { + direct->addr = old_addr; + if (unlikely(new_direct)) { + direct->count++; + list_del_rcu(&new_direct->next); + synchronize_rcu_tasks(); + kfree(new_direct); + ftrace_direct_func_count--; + } } out_unlock: |