lkml.org 
[lkml]   [2022]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net v2] netrom: fix sleep in atomic context bugs in timer handlers
Date
There are sleep in atomic context bugs in timer handlers of netrom
such as nr_t1timer_expiry(), nr_t2timer_expiry(), nr_heartbeat_expiry(),
nr_idletimer_expiry() and so on.

The root cause is kmemdup() with GFP_KERNEL parameter that may sleep
could be called by different timer handlers which is in interrupt context.

One of the call paths that could trigger bug is shown below:

(interrupt context)
nr_heartbeat_expiry
nr_write_internal
nr_transmit_buffer
nr_route_frame
nr_add_node
kmemdup(..,GFP_KERNEL) //may sleep

This patch changes gfp_t parameter of kmemdup in nr_add_node()
from GFP_KERNEL to GFP_ATOMIC in order to prevent sleep in atomic
context bugs.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
---
Changes in v2:
- Correct the "Fixes" tag.

net/netrom/nr_route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index baea3cbd76c..1ddcf13de6a 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -163,7 +163,7 @@ static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
nr_neigh->digipeat = kmemdup(ax25_digi,
sizeof(*ax25_digi),
- GFP_KERNEL);
+ GFP_ATOMIC);
if (nr_neigh->digipeat == NULL) {
kfree(nr_neigh);
if (nr_node)
--
2.17.1
\
 
 \ /
  Last update: 2022-07-26 05:26    [W:0.088 / U:0.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site