From 0f166bf1d6d82701cc1d94445cc2a9107d1790df Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Tue, 23 Dec 2025 08:00:39 +0100 Subject: [PATCH] select: store end_time as timespec64 in restart block MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Storing the end time seconds as 'unsigned long' can lead to truncation on 32-bit architectures if assigned from the 64-bit timespec64::tv_sec. As the select() core uses timespec64 consistently, also use that in the restart block. This also allows the simplification of the accessors. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20251223-restart-block-expiration-v2-1-8e33e5df7359@linutronix.de Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/select.c | 12 ++++-------- include/linux/restart_block.h | 4 ++-- 2 files changed, 6 insertions(+), 10 deletions(-) diff --git a/fs/select.c b/fs/select.c index 65019b8ba3f74..78a1508c84d3d 100644 --- a/fs/select.c +++ b/fs/select.c @@ -1038,14 +1038,11 @@ static long do_restart_poll(struct restart_block *restart_block) { struct pollfd __user *ufds = restart_block->poll.ufds; int nfds = restart_block->poll.nfds; - struct timespec64 *to = NULL, end_time; + struct timespec64 *to = NULL; int ret; - if (restart_block->poll.has_timeout) { - end_time.tv_sec = restart_block->poll.tv_sec; - end_time.tv_nsec = restart_block->poll.tv_nsec; - to = &end_time; - } + if (restart_block->poll.has_timeout) + to = &restart_block->poll.end_time; ret = do_sys_poll(ufds, nfds, to); @@ -1077,8 +1074,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, restart_block->poll.nfds = nfds; if (timeout_msecs >= 0) { - restart_block->poll.tv_sec = end_time.tv_sec; - restart_block->poll.tv_nsec = end_time.tv_nsec; + restart_block->poll.end_time = end_time; restart_block->poll.has_timeout = 1; } else restart_block->poll.has_timeout = 0; diff --git a/include/linux/restart_block.h b/include/linux/restart_block.h index 67d2bf5799428..9b262109726d2 100644 --- a/include/linux/restart_block.h +++ b/include/linux/restart_block.h @@ -6,6 +6,7 @@ #define __LINUX_RESTART_BLOCK_H #include +#include #include struct __kernel_timespec; @@ -50,8 +51,7 @@ struct restart_block { struct pollfd __user *ufds; int nfds; int has_timeout; - unsigned long tv_sec; - unsigned long tv_nsec; + struct timespec64 end_time; } poll; }; }; -- 2.47.3