linux/net/nfc
Duoming Zhou 4071bf121d 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: 9674da8759 ("NFC: Add firmware upload netlink command")
Fixes: 9ea7187c53 ("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>
2022-05-05 10:18:15 +02:00
..
hci nfc: drop unneeded debug prints 2021-10-11 17:00:51 -07:00
nci nfc: nci: add flush_workqueue to prevent uaf 2022-04-13 14:44:44 +01:00
af_nfc.c nfc: fix error handling of nfc_proto_register() 2021-10-13 17:32:38 -07:00
core.c nfc: replace improper check device_is_registered() in netlink related functions 2022-05-01 13:26:05 +01:00
digital_core.c NFC: digital: fix possible memory leak in digital_tg_listen_mdaa() 2021-10-13 17:44:29 -07:00
digital_dep.c
digital_technology.c NFC: digital: fix possible memory leak in digital_in_send_sdd_req() 2021-10-13 17:44:29 -07:00
digital.h
Kconfig
llcp_commands.c nfc: drop unneeded debug prints 2021-10-11 17:00:51 -07:00
llcp_core.c nfc: llcp: Revert "NFC: Keep socket alive until the DISC PDU is actually sent" 2022-03-03 10:43:37 +00:00
llcp_sock.c nfc: llcp: Revert "NFC: Keep socket alive until the DISC PDU is actually sent" 2022-03-03 10:43:37 +00:00
llcp.h nfc: llcp: Revert "NFC: Keep socket alive until the DISC PDU is actually sent" 2022-03-03 10:43:37 +00:00
Makefile
netlink.c NFC: netlink: fix sleep in atomic bug when firmware download timeout 2022-05-05 10:18:15 +02:00
nfc.h nfc: constify several pointers to u8, char and sk_buff 2021-07-30 17:22:52 +02:00
rawsock.c net: in_irq() cleanup 2021-08-13 14:09:19 -07:00