<kevin_yang@xxxxxxxxxxx> writes: > From: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx> > > In MLD connection, link_data/link_conf are dynamically allocated. They > don't point to vif->bss_conf. So, there will be no chanreq assigned to > vif->bss_conf and then the chan will be NULL. To get deflink's chanreq, > we change the code to access vif->link_conf with deflink's link id. > > This way should also work in non-MLD connection, because non-MLD deflink > link id should be 0 and non-MLD link_conf[0] will point to vif->bss_conf. > > Crash log (with rtw89 version under MLO development): > [ 9890.526087] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [ 9890.526102] #PF: supervisor read access in kernel mode > [ 9890.526105] #PF: error_code(0x0000) - not-present page > [ 9890.526109] PGD 0 P4D 0 > [ 9890.526114] Oops: 0000 [#1] PREEMPT SMP PTI > [ 9890.526119] CPU: 2 PID: 6367 Comm: kworker/u16:2 Kdump: loaded Tainted: G OE 6.9.0 #1 > [ 9890.526123] Hardware name: LENOVO 2356AD1/2356AD1, BIOS G7ETB3WW (2.73 ) 11/28/2018 > [ 9890.526126] Workqueue: phy2 rtw89_core_ba_work [rtw89_core] > [ 9890.526203] RIP: 0010:ieee80211_start_tx_ba_session (net/mac80211/agg-tx.c:618 (discriminator 1)) mac80211 > [ 9890.526279] Code: f7 e8 d5 93 3e ea 48 83 c4 28 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 49 8b 84 24 e0 f1 ff ff 48 8b 80 90 1b 00 00 <83> 38 03 0f 84 37 fe ff ff bb ea ff ff ff eb cc 49 8b 84 24 10 f3 > All code > ======== > 0: f7 e8 imul %eax > 2: d5 (bad) > 3: 93 xchg %eax,%ebx > 4: 3e ea ds (bad) > 6: 48 83 c4 28 add $0x28,%rsp > a: 89 d8 mov %ebx,%eax > c: 5b pop %rbx > d: 41 5c pop %r12 > f: 41 5d pop %r13 > 11: 41 5e pop %r14 > 13: 41 5f pop %r15 > 15: 5d pop %rbp > 16: c3 retq > 17: cc int3 > 18: cc int3 > 19: cc int3 > 1a: cc int3 > 1b: 49 8b 84 24 e0 f1 ff mov -0xe20(%r12),%rax > 22: ff > 23: 48 8b 80 90 1b 00 00 mov 0x1b90(%rax),%rax > 2a:* 83 38 03 cmpl $0x3,(%rax) <-- trapping instruction > 2d: 0f 84 37 fe ff ff je 0xfffffffffffffe6a > 33: bb ea ff ff ff mov $0xffffffea,%ebx > 38: eb cc jmp 0x6 > 3a: 49 rex.WB > 3b: 8b .byte 0x8b > 3c: 84 24 10 test %ah,(%rax,%rdx,1) > 3f: f3 repz > > Code starting with the faulting instruction > =========================================== > 0: 83 38 03 cmpl $0x3,(%rax) > 3: 0f 84 37 fe ff ff je 0xfffffffffffffe40 > 9: bb ea ff ff ff mov $0xffffffea,%ebx > e: eb cc jmp 0xffffffffffffffdc > 10: 49 rex.WB > 11: 8b .byte 0x8b > 12: 84 24 10 test %ah,(%rax,%rdx,1) > 15: f3 repz > [ 9890.526285] RSP: 0018:ffffb8db09013d68 EFLAGS: 00010246 > [ 9890.526291] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9308e0d656c8 > [ 9890.526295] RDX: 0000000000000000 RSI: ffffffffab99460b RDI: ffffffffab9a7685 > [ 9890.526300] RBP: ffffb8db09013db8 R08: 0000000000000000 R09: 0000000000000873 > [ 9890.526304] R10: ffff9308e0d64800 R11: 0000000000000002 R12: ffff9308e5ff6e70 > [ 9890.526308] R13: ffff930952500e20 R14: ffff9309192a8c00 R15: 0000000000000000 > [ 9890.526313] FS: 0000000000000000(0000) GS:ffff930b4e700000(0000) knlGS:0000000000000000 > [ 9890.526316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 9890.526318] CR2: 0000000000000000 CR3: 0000000391c58005 CR4: 00000000001706f0 > [ 9890.526321] Call Trace: > [ 9890.526324] <TASK> > [ 9890.526327] ? show_regs (arch/x86/kernel/dumpstack.c:479) > [ 9890.526335] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) > [ 9890.526340] ? page_fault_oops (arch/x86/mm/fault.c:713) > [ 9890.526347] ? search_module_extables (kernel/module/main.c:3256 (discriminator 3)) > [ 9890.526353] ? ieee80211_start_tx_ba_session (net/mac80211/agg-tx.c:618 (discriminator 1)) mac80211 > > Signed-off-by: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx> Kevin's s-o-b missing. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
