From b6855772f4a22c4fbdd4fcaceff5c8a527035123 Mon Sep 17 00:00:00 2001 From: Bob Copeland Date: Fri, 18 Jun 2010 13:15:23 -0400 Subject: [PATCH] ath5k: initialize ah->ah_current_channel ath5k assumes ah_current_channel is always a valid pointer in several places, but a newly created interface may not have a channel. To avoid null pointer dereferences, set it up to point to the first available channel until later reconfigured. This fixes the following oops: $ rmmod ath5k $ insmod ath5k $ iw phy0 set distance 11000 BUG: unable to handle kernel NULL pointer dereference at 00000006 IP: [] ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k] *pde = 00000000 Oops: 0000 [#1] last sysfs file: /sys/devices/pci0000:00/0000:00:0e.0/ieee80211/phy0/index Modules linked in: usbhid option usb_storage usbserial usblp evdev lm90 scx200_acb i2c_algo_bit i2c_dev i2c_core via_rhine ohci_hcd ne2k_pci 8390 leds_alix2 xt_IMQ imq nf_nat_tftp nf_conntrack_tftp nf_nat_irc nf_cc Pid: 1597, comm: iw Not tainted (2.6.32.14 #8) EIP: 0060:[] EFLAGS: 00010296 CPU: 0 EIP is at ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k] EAX: 000000c2 EBX: 00000000 ECX: ffffffff EDX: c12d2080 ESI: 00000019 EDI: cf8c0000 EBP: d0a30edc ESP: cfa09bf4 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 Process iw (pid: 1597, ti=cfa09000 task=cf88a000 task.ti=cfa09000) Stack: d0a34f35 d0a353f8 d0a30edc 000000fe cf8c0000 00000000 1900063d cfa8c9e0 <0> cfa8c9e8 cfa8c0c0 cfa8c000 d0a27f0c 199d84b4 cfa8c200 00000010 d09bfdc7 <0> 00000000 00000000 ffffffff d08e0d28 cf9263c0 00000001 cfa09cc4 00000000 Call Trace: [] ? ath5k_hw_attach+0xc8c/0x3c10 [ath5k] [] ? __ieee80211_request_smps+0x1347/0x1580 [mac80211] [] ? nl80211_send_scan_start+0x7b8/0x4520 [cfg80211] [] ? nla_parse+0x59/0xc0 [] ? genl_rcv_msg+0x169/0x1a0 [] ? genl_rcv_msg+0x0/0x1a0 [] ? netlink_rcv_skb+0x38/0x90 [] ? genl_rcv+0x19/0x30 [] ? netlink_unicast+0x1b3/0x220 [] ? netlink_sendmsg+0x26e/0x290 [] ? sock_sendmsg+0xbe/0xf0 [] ? autoremove_wake_function+0x0/0x50 [] ? __alloc_pages_nodemask+0x106/0x530 [] ? do_lookup+0x53/0x1b0 [] ? __link_path_walk+0x9b9/0x9e0 [] ? verify_iovec+0x50/0x90 [] ? sys_sendmsg+0x1e1/0x270 [] ? find_get_page+0x10/0x50 [] ? filemap_fault+0x5f/0x370 [] ? __do_fault+0x319/0x370 [] ? sys_socketcall+0x244/0x290 [] ? do_page_fault+0x1ec/0x270 [] ? do_page_fault+0x0/0x270 [] ? syscall_call+0x7/0xb Code: 00 b8 fe 00 00 00 b9 f8 53 a3 d0 89 5c 24 14 89 7c 24 10 89 44 24 0c 89 6c 24 08 89 4c 24 04 c7 04 24 35 4f a3 d0 e8 7c 30 60 f0 <0f> b7 43 06 ba 06 00 00 00 a8 10 75 0e 83 e0 20 83 f8 01 19 d2 EIP: [] ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k] SS:ESP 0068:cfa09bf4 CR2: 0000000000000006 ---[ end trace 54f73d6b10ceb87b ]--- Cc: stable@kernel.org Reported-by: Steve Brown Signed-off-by: Bob Copeland Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath5k/attach.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/wireless/ath/ath5k/attach.c b/drivers/net/wireless/ath/ath5k/attach.c index e0c244b..31c0080 100644 --- a/drivers/net/wireless/ath/ath5k/attach.c +++ b/drivers/net/wireless/ath/ath5k/attach.c @@ -126,6 +126,7 @@ int ath5k_hw_attach(struct ath5k_softc *sc) ah->ah_ant_mode = AR5K_ANTMODE_DEFAULT; ah->ah_noise_floor = -95; /* until first NF calibration is run */ sc->ani_state.ani_mode = ATH5K_ANI_MODE_AUTO; + ah->ah_current_channel = &sc->channels[0]; /* * Find the mac version -- 2.7.4