From 8e484ebb1edc8329e1f7c527d556038a395f654e Mon Sep 17 00:00:00 2001 From: Hayes Wang Date: Wed, 23 Oct 2019 21:24:44 +0800 Subject: [PATCH] r8152: check the pointer rtl_fw->fw before using it Fix the pointer rtl_fw->fw would be used before checking in rtl8152_apply_firmware() that causes the following kernel oops. Unable to handle kernel NULL pointer dereference at virtual address 00000002 pgd = (ptrval) [00000002] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 131 Comm: kworker/0:2 Not tainted 5.4.0-rc1-00539-g9370f2d05a2a #6788 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) Workqueue: events_long rtl_hw_phy_work_func_t PC is at rtl8152_apply_firmware+0x14/0x464 LR is at r8153_hw_phy_cfg+0x24/0x17c pc : [] lr : [] psr: a0000013 sp : e75c9e60 ip : 60000013 fp : c11b7614 r10: e883b91c r9 : 00000000 r8 : fffffffe r7 : e883b640 r6 : fffffffe r5 : fffffffe r4 : e883b640 r3 : 736cfe7c r2 : 736cfe7c r1 : 000052f8 r0 : e883b640 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 6640006a DAC: 00000051 Process kworker/0:2 (pid: 131, stack limit = 0x(ptrval)) Stack: (0xe75c9e60 to 0xe75ca000) ... [] (rtl8152_apply_firmware) from [] (r8153_hw_phy_cfg+0x24/0x17c) [] (r8153_hw_phy_cfg) from [] (rtl_hw_phy_work_func_t+0x220/0x3e4) [] (rtl_hw_phy_work_func_t) from [] (process_one_work+0x22c/0x7c8) [] (process_one_work) from [] (worker_thread+0x44/0x520) [] (worker_thread) from [] (kthread+0x130/0x164) [] (kthread) from [] (ret_from_fork+0x14/0x20) Exception stack(0xe75c9fb0 to 0xe75c9ff8) ... Fixes: 9370f2d05a2a ("r8152: support request_firmware for RTL8153") Reported-by: Marek Szyprowski Tested-by: Marek Szyprowski Signed-off-by: Hayes Wang Signed-off-by: David S. Miller --- drivers/net/usb/r8152.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index d3c30ccc8577..283b35a76cf0 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -4000,8 +4000,8 @@ static void rtl8152_fw_mac_apply(struct r8152 *tp, struct fw_mac *mac) static void rtl8152_apply_firmware(struct r8152 *tp) { struct rtl_fw *rtl_fw = &tp->rtl_fw; - const struct firmware *fw = rtl_fw->fw; - struct fw_header *fw_hdr = (struct fw_header *)fw->data; + const struct firmware *fw; + struct fw_header *fw_hdr; struct fw_phy_patch_key *key; u16 key_addr = 0; int i; @@ -4009,6 +4009,9 @@ static void rtl8152_apply_firmware(struct r8152 *tp) if (IS_ERR_OR_NULL(rtl_fw->fw)) return; + fw = rtl_fw->fw; + fw_hdr = (struct fw_header *)fw->data; + if (rtl_fw->pre_fw) rtl_fw->pre_fw(tp);