From: Duoming Zhou <duoming@zju.edu.cn> stable inclusion from stable-v5.10.115 commit 879b075a9a364a325988d4484b74311edfef82a1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5C0OU CVE: CVE-2022-1975 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 4071bf121d59944d5cd2238de0642f3d7995a997 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Xu Jia <xujia39@huawei.com> Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- net/nfc/netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index 72d1e29e28b2..f5c816a18b9c 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; -- 2.20.1