diff options
| author | Rosen Penev <rosenp@gmail.com> | 2026-06-03 16:08:21 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-08 17:35:50 -0700 |
| commit | 7c5d41f87f079990bf241359e3c1332d8d10fe87 (patch) | |
| tree | d81aec3078acdef6c252f61f4b7002ed98e1903b | |
| parent | f0ba7f385de12d237f31c9439256647b25294a01 (diff) | |
| download | linux-stable-7c5d41f87f079990bf241359e3c1332d8d10fe87.tar.gz linux-stable-7c5d41f87f079990bf241359e3c1332d8d10fe87.zip | |
net: ibm: emac: mal: fix potential system hang in mal_remove()
napi_disable() is not idempotent and calling it on an already-disabled
or unenabled NAPI context will cause the kernel to spin indefinitely
waiting for the NAPI_STATE_SCHED bit to clear.
In mal_remove(), napi_disable() is called unconditionally. If no MACs were
registered, NAPI was never enabled. Also, if they were registered but
subsequently unregistered, NAPI was already disabled in
mal_unregister_commac(). In either case, calling napi_disable() causes
the kernel to hang upon module removal.
Fix this by only calling napi_disable() in mal_remove() if the commac list
is not empty (which implies NAPI is enabled).
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260603230821.5619-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/ibm/emac/mal.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/ethernet/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c index 83dd7f99d8d5..74526002d52b 100644 --- a/drivers/net/ethernet/ibm/emac/mal.c +++ b/drivers/net/ethernet/ibm/emac/mal.c @@ -712,13 +712,13 @@ static void mal_remove(struct platform_device *ofdev) MAL_DBG(mal, "remove" NL); /* Synchronize with scheduled polling */ - napi_disable(&mal->napi); - - if (!list_empty(&mal->list)) + if (!list_empty(&mal->list)) { + napi_disable(&mal->napi); /* This is *very* bad */ WARN(1, KERN_EMERG "mal%d: commac list is not empty on remove!\n", mal->index); + } mal_reset(mal); |