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| author |   Duoming Zhou <duoming@zju.edu.cn> | 2022-05-04 13:58:47 +0800 |
|---|---|---|
| committer |   Paolo Abeni <pabeni@redhat.com> | 2022-05-05 10:18:15 +0200 |
| commit | 4071bf121d59944d5cd2238de0642f3d7995a997 (patch) | |
| tree | 5a599ce347e5a6c4f6f3ff6b371f139d8262c3f9 | |
| parent | selftests: ocelot: tc_flower_chains: specify conform-exceed action for policer (diff) | |
| download | wireguard-linux-4071bf121d59944d5cd2238de0642f3d7995a997.tar.xz wireguard-linux-4071bf121d59944d5cd2238de0642f3d7995a997.zip | |
NFC: netlink: fix sleep in atomic bug when firmware download timeout
There are sleep in atomic bug that could cause kernel panic during
firmware download process. The root cause is that nlmsg_new with
GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer
handler. The call trace is shown below:
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
Call Trace:
kmem_cache_alloc_node
__alloc_skb
nfc_genl_fw_download_done
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
...
The nlmsg_new with GFP_KERNEL parameter may sleep during memory
allocation process, and the timer handler is run as the result of
a "software interrupt" that should not call any other function
that could sleep.
This patch changes allocation mode of netlink message from GFP_KERNEL
to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.
Fixes: 9674da8759df ("NFC: Add firmware upload netlink command")
Fixes: 9ea7187c53f6 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/nfc/netlink.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index f184b0db79d4..7c62417ccfd7 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -1244,7 +1244,7 @@ int nfc_genl_fw_download_done(struct nfc_dev *dev, const char *firmware_name, struct sk_buff *msg; void *hdr; - msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!msg) return -ENOMEM; @@ -1260,7 +1260,7 @@ int nfc_genl_fw_download_done(struct nfc_dev *dev, const char *firmware_name, genlmsg_end(msg, hdr); - genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL); + genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_ATOMIC); return 0; |