| Message ID | 20211021034516.4400-3-laoar.shao@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | extend task comm from 16 to 24 for CONFIG_BASE_FULL | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
| bpf/vmtest-bpf-next-PR | fail | merge-conflict |
| bpf/vmtest-bpf | success | VM_Test |
| bpf/vmtest-bpf-PR | success | PR summary |
diff --git a/fs/exec.c b/fs/exec.c index 404156b5b314..bf2a7a91eeea 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1209,7 +1209,8 @@ static int unshare_sighand(struct task_struct *me) char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk) { task_lock(tsk); - strncpy(buf, tsk->comm, buf_size); + /* The copied value is always null terminated */ + strscpy_pad(buf, tsk->comm, buf_size); task_unlock(tsk); return buf; }
If the dest buffer size is smaller than sizeof(tsk->comm), the buffer will be without null ternimator, that may cause problem. We can make sure the buffer size not smaller than comm at the callsite to avoid that problem, but there may be callsite that we can't easily change. Using strscpy_pad() instead of strncpy() in __get_task_comm() can make the string always nul ternimated. Suggested-by: Kees Cook <keescook@chromium.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Petr Mladek <pmladek@suse.com> --- fs/exec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)