From: Dmitry Safonov dima@arista.com
[ Upstream commit 01c195de620bb6c3ecda0dbf295fe685d8232e10 ]
bindex can be out of BA window (64): tid 0 seq 2983, start_seq 2915, bindex 68, index 39 tid 0 seq 2984, start_seq 2915, bindex 69, index 40 tid 0 seq 2985, start_seq 2915, bindex 70, index 41 tid 0 seq 2986, start_seq 2915, bindex 71, index 42 tid 0 seq 2879, start_seq 2915, bindex 4060, index 63 tid 0 seq 2854, start_seq 2915, bindex 4035, index 38 tid 0 seq 2795, start_seq 2915, bindex 3976, index 43 tid 0 seq 2989, start_seq 2924, bindex 65, index 45 tid 0 seq 2992, start_seq 2924, bindex 68, index 48 tid 0 seq 2993, start_seq 2924, bindex 69, index 49 tid 0 seq 2994, start_seq 2924, bindex 70, index 50 tid 0 seq 2997, start_seq 2924, bindex 73, index 53 tid 0 seq 2795, start_seq 2941, bindex 3950, index 43 tid 0 seq 2921, start_seq 2941, bindex 4076, index 41 tid 0 seq 2929, start_seq 2941, bindex 4084, index 49 tid 0 seq 3011, start_seq 2946, bindex 65, index 3 tid 0 seq 3012, start_seq 2946, bindex 66, index 4 tid 0 seq 3013, start_seq 2946, bindex 67, index 5
In result isset() will try to dereference something on the stack, causing panics: BUG: unable to handle page fault for address: ffffa742800ed01f #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 6a4e9067 P4D 6a4e9067 PUD 6a4ec067 PMD 6a4ed067 PTE 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Not tainted 5.8.5-arch1-1-kdump #1 Hardware name: Apple Inc. MacBookAir3,1/Mac-942452F5819B1C1B, BIOS MBA31.88Z.0061.B07.1201241641 01/24/12 RIP: 0010:brcms_c_ampdu_dotxstatus+0x343/0x9f0 [brcmsmac] Code: 54 24 20 66 81 e2 ff 0f 41 83 e4 07 89 d1 0f b7 d2 66 c1 e9 03 0f b7 c9 4c 8d 5c 0c 48 49 8b 4d 10 48 8b 79 68 41 57 44 89 e1 <41> 0f b6 33 41 d3 e0 48 c7 c1 38 e0 ea c0 48 83 c7 10 44 21 c6 4c RSP: 0018:ffffa742800ecdd0 EFLAGS: 00010207 RAX: 0000000000000019 RBX: 000000000000000b RCX: 0000000000000006 RDX: 0000000000000ffe RSI: 0000000000000004 RDI: ffff8fc6ad776800 RBP: ffff8fc6855acb00 R08: 0000000000000001 R09: 00000000000005d9 R10: 00000000fffffffe R11: ffffa742800ed01f R12: 0000000000000006 R13: ffff8fc68d75a000 R14: 00000000000005db R15: 0000000000000019 FS: 0000000000000000(0000) GS:ffff8fc6aad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa742800ed01f CR3: 000000002480a000 CR4: 00000000000406e0 Call Trace: <IRQ> brcms_c_dpc+0xb46/0x1020 [brcmsmac] ? wlc_intstatus+0xc8/0x180 [brcmsmac] ? __raise_softirq_irqoff+0x1a/0x80 brcms_dpc+0x37/0xd0 [brcmsmac] tasklet_action_common.constprop.0+0x51/0xb0 __do_softirq+0xff/0x340 ? handle_level_irq+0x1a0/0x1a0 asm_call_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x5f/0x80 irq_exit_rcu+0xcb/0x120 common_interrupt+0xd1/0x200 asm_common_interrupt+0x1e/0x40 RIP: 0010:cpuidle_enter_state+0xb3/0x420
Check if the block is within BA window and only then check block's status. Otherwise as Behan wrote: "When I came back to Dublin I was courtmartialed in my absence and sentenced to death in my absence, so I said they could shoot me in my absence."
Also reported: https://bbs.archlinux.org/viewtopic.php?id=258428 https://lore.kernel.org/linux-wireless/87tuwgi92n.fsf@yujinakao.com/
Reported-by: Yuji Nakao contact@yujinakao.com Signed-off-by: Dmitry Safonov dima@arista.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/20201116030635.645811-1-dima@arista.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/wireless/broadcom/brcm80211/brcmsmac/ampdu.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/ampdu.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/ampdu.c index fa391e4eb0989..44f65b8bff9e0 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/ampdu.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/ampdu.c @@ -953,14 +953,19 @@ brcms_c_ampdu_dotxstatus_complete(struct ampdu_info *ampdu, struct scb *scb, index = TX_SEQ_TO_INDEX(seq); ack_recd = false; if (ba_recd) { + int block_acked; + bindex = MODSUB_POW2(seq, start_seq, SEQNUM_MAX); + if (bindex < AMPDU_TX_BA_MAX_WSIZE) + block_acked = isset(bitmap, bindex); + else + block_acked = 0; brcms_dbg_ht(wlc->hw->d11core, "tid %d seq %d, start_seq %d, bindex %d set %d, index %d\n", tid, seq, start_seq, bindex, - isset(bitmap, bindex), index); + block_acked, index); /* if acked then clear bit and free packet */ - if ((bindex < AMPDU_TX_BA_MAX_WSIZE) - && isset(bitmap, bindex)) { + if (block_acked) { ini->txretry[index] = 0;
/*