Messages in this thread Patch in this message | | | From | Hongchen Zhang <> | Subject | [PATCH] signal: strict valid signal check | Date | Fri, 7 Jan 2022 12:45:57 +0800 |
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The max usable signal number is limited by both _NSIG and task's exit_code, and the max valid signal number encoded in task's exit_code is 127. On the other hand _NSIG is normally power of 2, so limit the rule in valid_signal to check a valid signal number.
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn> --- include/linux/signal.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/signal.h b/include/linux/signal.h index a6db6f2..9f1972e 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -270,7 +270,11 @@ static inline void init_sigpending(struct sigpending *sig) /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */ static inline int valid_signal(unsigned long sig) { - return sig <= _NSIG ? 1 : 0; + /* max usable signal number is limited by both _NSIG and task's + * exit_code, and the max available signal number encoded in + * task's exit_code is 127. + */ + return sig <= min(_NSIG, 127) ? 1 : 0; } struct timespec; -- 1.8.3.1
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