Messages in this thread Patch in this message | | | From | Duoming Zhou <> | Subject | [PATCH net v2] netrom: fix sleep in atomic context bugs in timer handlers | Date | Tue, 26 Jul 2022 11:24:20 +0800 |
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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
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