diff mbox series

[v2,04/11] net/smc: smc_splice_read: always request MSG_DONTWAIT

Message ID 38e20a4939603718232859ee2170f54d8bcd8ddf.1703126594.git.nabijaczleweli@nabijaczleweli.xyz (mailing list archive)
State New
Headers show
Series Avoid unprivileged splice(file->)/(->socket) pipe exclusion | expand

Commit Message

Ahelenia Ziemiańska Dec. 21, 2023, 3:09 a.m. UTC 
Otherwise we risk sleeping with the pipe locked for indeterminate
lengths of time ‒ this meant that splice(smc -> pipe) with no data
would hold the pipe lock, and any open/read/write/close on the pipe
would enter uninterruptible sleep.

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
---
 net/smc/af_smc.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 73eebddbbf41..a11a966d031a 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3248,12 +3248,8 @@  static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
 			rc = -ESPIPE;
 			goto out;
 		}
-		if (flags & SPLICE_F_NONBLOCK)
-			flags = MSG_DONTWAIT;
-		else
-			flags = 0;
 		SMC_STAT_INC(smc, splice_cnt);
-		rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
+		rc = smc_rx_recvmsg(smc, NULL, pipe, len, MSG_DONTWAIT);
 	}
 out:
 	release_sock(sk);