In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix potencial out-of-bounds when buffer offset is invalid I found potencial out-of-bounds when buffer offset fields of a few requests is invalid. This patch set the minimum value of buffer offset field to ->Buffer offset to validate buffer length.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/pm: Fix NULL pointer dereference when get power limit Because powerplay_table initialization is skipped under sriov case, We check and set default lower and upper OD value if powerplay_table is NULL.

In the Linux kernel, the following vulnerability has been resolved: USB: core: Fix deadlock in usb_deauthorize_interface() Among the attribute file callback routines in drivers/usb/core/sysfs.c, the interface_authorized_store() function is the only one which acquires a device lock on an ancestor device: It calls usb_deauthorize_interface(), which locks the interface's parent USB device. The will lead to deadlock if another process already owns that lock and tries to remove the interface, whether through a configuration change or because the device has been disconnected. As part of the removal procedure, device_del() waits for all ongoing sysfs attribute callbacks to complete. But usb_deauthorize_interface() can't complete until the device lock has been released, and the lock won't be released until the removal has finished. The mechanism provided by sysfs to prevent this kind of deadlock is to use the sysfs_break_active_protection() function, which tells sysfs not to wait for the attribute callback. Reported-and-tested by: Yue Sun <samsun1006219@gmail.com> Reported by: xingwei lee <xrivendell7@gmail.com>

In the Linux kernel, the following vulnerability has been resolved: USB: core: Fix deadlock in port "disable" sysfs attribute The show and store callback routines for the "disable" sysfs attribute file in port.c acquire the device lock for the port's parent hub device. This can cause problems if another process has locked the hub to remove it or change its configuration: Removing the hub or changing its configuration requires the hub interface to be removed, which requires the port device to be removed, and device_del() waits until all outstanding sysfs attribute callbacks for the ports have returned. The lock can't be released until then. But the disable_show() or disable_store() routine can't return until after it has acquired the lock. The resulting deadlock can be avoided by calling sysfs_break_active_protection(). This will cause the sysfs core not to wait for the attribute's callback routine to return, allowing the removal to proceed. The disadvantage is that after making this call, there is no guarantee that the hub structure won't be deallocated at any moment. To prevent this, we have to acquire a reference to it first by calling hub_get().

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix double free of the ha->vp_map pointer Coverity scan reported potential risk of double free of the pointer ha->vp_map. ha->vp_map was freed in qla2x00_mem_alloc(), and again freed in function qla2x00_mem_free(ha). Assign NULL to vp_map and kfree take care of NULL.

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix double free of fcport The server was crashing after LOGO because fcport was getting freed twice. -----------[ cut here ]----------- kernel BUG at mm/slub.c:371! invalid opcode: 0000 1 SMP PTI CPU: 35 PID: 4610 Comm: bash Kdump: loaded Tainted: G OE --------- - - 4.18.0-425.3.1.el8.x86_64 #1 Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 09/03/2021 RIP: 0010:set_freepointer.part.57+0x0/0x10 RSP: 0018:ffffb07107027d90 EFLAGS: 00010246 RAX: ffff9cb7e3150000 RBX: ffff9cb7e332b9c0 RCX: ffff9cb7e3150400 RDX: 0000000000001f37 RSI: 0000000000000000 RDI: ffff9cb7c0005500 RBP: fffff693448c5400 R08: 0000000080000000 R09: 0000000000000009 R10: 0000000000000000 R11: 0000000000132af0 R12: ffff9cb7c0005500 R13: ffff9cb7e3150000 R14: ffffffffc06990e0 R15: ffff9cb7ea85ea58 FS: 00007ff6b79c2740(0000) GS:ffff9cb8f7ec0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b426b7d700 CR3: 0000000169c18002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: kfree+0x238/0x250 qla2x00_els_dcmd_sp_free+0x20/0x230 [qla2xxx] ? qla24xx_els_dcmd_iocb+0x607/0x690 [qla2xxx] qla2x00_issue_logo+0x28c/0x2a0 [qla2xxx] ? qla2x00_issue_logo+0x28c/0x2a0 [qla2xxx] ? kernfs_fop_write+0x11e/0x1a0 Remove one of the free calls and add check for valid fcport. Also use function qla2x00_free_fcport() instead of kfree().

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gem: Really move i915_gem_context.link under ref protection i915_perf assumes that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration. However, this requires that we do not remove the context from the list until after we drop the final reference and release the struct. If, as currently, we remove the context from the list during context_close(), the link.next pointer may be poisoned while we are holding the context reference and cause a GPF: [ 4070.573157] i915 0000:00:02.0: [drm:i915_perf_open_ioctl [i915]] filtering on ctx_id=0x1fffff ctx_id_mask=0x1fffff [ 4070.574881] general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP [ 4070.574897] CPU: 1 PID: 284392 Comm: amd_performance Tainted: G E 5.17.9 #180 [ 4070.574903] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017 [ 4070.574907] RIP: 0010:oa_configure_all_contexts.isra.0+0x222/0x350 [i915] [ 4070.574982] Code: 08 e8 32 6e 10 e1 4d 8b 6d 50 b8 ff ff ff ff 49 83 ed 50 f0 41 0f c1 04 24 83 f8 01 0f 84 e3 00 00 00 85 c0 0f 8e fa 00 00 00 <49> 8b 45 50 48 8d 70 b0 49 8d 45 50 48 39 44 24 10 0f 85 34 fe ff [ 4070.574990] RSP: 0018:ffffc90002077b78 EFLAGS: 00010202 [ 4070.574995] RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000000 [ 4070.575000] RDX: 0000000000000001 RSI: ffffc90002077b20 RDI: ffff88810ddc7c68 [ 4070.575004] RBP: 0000000000000001 R08: ffff888103242648 R09: fffffffffffffffc [ 4070.575008] R10: ffffffff82c50bc0 R11: 0000000000025c80 R12: ffff888101bf1860 [ 4070.575012] R13: dead0000000000b0 R14: ffffc90002077c04 R15: ffff88810be5cabc [ 4070.575016] FS: 00007f1ed50c0780(0000) GS:ffff88885ec80000(0000) knlGS:0000000000000000 [ 4070.575021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4070.575025] CR2: 00007f1ed5590280 CR3: 000000010ef6f005 CR4: 00000000003706e0 [ 4070.575029] Call Trace: [ 4070.575033] <TASK> [ 4070.575037] lrc_configure_all_contexts+0x13e/0x150 [i915] [ 4070.575103] gen8_enable_metric_set+0x4d/0x90 [i915] [ 4070.575164] i915_perf_open_ioctl+0xbc0/0x1500 [i915] [ 4070.575224] ? asm_common_interrupt+0x1e/0x40 [ 4070.575232] ? i915_oa_init_reg_state+0x110/0x110 [i915] [ 4070.575290] drm_ioctl_kernel+0x85/0x110 [ 4070.575296] ? update_load_avg+0x5f/0x5e0 [ 4070.575302] drm_ioctl+0x1d3/0x370 [ 4070.575307] ? i915_oa_init_reg_state+0x110/0x110 [i915] [ 4070.575382] ? gen8_gt_irq_handler+0x46/0x130 [i915] [ 4070.575445] __x64_sys_ioctl+0x3c4/0x8d0 [ 4070.575451] ? __do_softirq+0xaa/0x1d2 [ 4070.575456] do_syscall_64+0x35/0x80 [ 4070.575461] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 4070.575467] RIP: 0033:0x7f1ed5c10397 [ 4070.575471] Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a9 da 0d 00 f7 d8 64 89 01 48 [ 4070.575478] RSP: 002b:00007ffd65c8d7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 4070.575484] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f1ed5c10397 [ 4070.575488] RDX: 00007ffd65c8d7c0 RSI: 0000000040106476 RDI: 0000000000000006 [ 4070.575492] RBP: 00005620972f9c60 R08: 000000000000000a R09: 0000000000000005 [ 4070.575496] R10: 000000000000000d R11: 0000000000000246 R12: 000000000000000a [ 4070.575500] R13: 000000000000000d R14: 0000000000000000 R15: 00007ffd65c8d7c0 [ 4070.575505] </TASK> [ 4070.575507] Modules linked in: nls_ascii(E) nls_cp437(E) vfat(E) fat(E) i915(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) aesni_intel(E) crypto_simd(E) intel_gtt(E) cryptd(E) ttm(E) rapl(E) intel_cstate(E) drm_kms_helper(E) cfbfillrect(E) syscopyarea(E) cfbimgblt(E) intel_uncore(E) sysfillrect(E) mei_me(E) sysimgblt(E) i2c_i801(E) fb_sys_fops(E) mei(E) intel_pch_thermal(E) i2c_smbus ---truncated---

In the Linux kernel, the following vulnerability has been resolved: gpio: mockup: Fix potential resource leakage when register a chip If creation of software node fails, the locally allocated string array is left unfreed. Free it on error path.

In the Linux kernel, the following vulnerability has been resolved: gpiolib: cdev: Set lineevent_state::irq after IRQ register successfully When running gpio test on nxp-ls1028 platform with below command gpiomon --num-events=3 --rising-edge gpiochip1 25 There will be a warning trace as below: Call trace: free_irq+0x204/0x360 lineevent_free+0x64/0x70 gpio_ioctl+0x598/0x6a0 __arm64_sys_ioctl+0xb4/0x100 invoke_syscall+0x5c/0x130 ...... el0t_64_sync+0x1a0/0x1a4 The reason of this issue is that calling request_threaded_irq() function failed, and then lineevent_free() is invoked to release the resource. Since the lineevent_state::irq was already set, so the subsequent invocation of free_irq() would trigger the above warning call trace. To fix this issue, set the lineevent_state::irq after the IRQ register successfully.

In the Linux kernel, the following vulnerability has been resolved: mm/slub: fix to return errno if kmalloc() fails In create_unique_id(), kmalloc(, GFP_KERNEL) can fail due to out-of-memory, if it fails, return errno correctly rather than triggering panic via BUG_ON(); kernel BUG at mm/slub.c:5893! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Call trace: sysfs_slab_add+0x258/0x260 mm/slub.c:5973 __kmem_cache_create+0x60/0x118 mm/slub.c:4899 create_cache mm/slab_common.c:229 [inline] kmem_cache_create_usercopy+0x19c/0x31c mm/slab_common.c:335 kmem_cache_create+0x1c/0x28 mm/slab_common.c:390 f2fs_kmem_cache_create fs/f2fs/f2fs.h:2766 [inline] f2fs_init_xattr_caches+0x78/0xb4 fs/f2fs/xattr.c:808 f2fs_fill_super+0x1050/0x1e0c fs/f2fs/super.c:4149 mount_bdev+0x1b8/0x210 fs/super.c:1400 f2fs_mount+0x44/0x58 fs/f2fs/super.c:4512 legacy_get_tree+0x30/0x74 fs/fs_context.c:610 vfs_get_tree+0x40/0x140 fs/super.c:1530 do_new_mount+0x1dc/0x4e4 fs/namespace.c:3040 path_mount+0x358/0x914 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __arm64_sys_mount+0x2f8/0x408 fs/namespace.c:3568

In the Linux kernel, the following vulnerability has been resolved: mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. Commit 5a836bf6b09f ("mm: slub: move flush_cpu_slab() invocations __free_slab() invocations out of IRQ context") moved all flush_cpu_slab() invocations to the global workqueue to avoid a problem related with deactivate_slab()/__free_slab() being called from an IRQ context on PREEMPT_RT kernels. When the flush_all_cpu_locked() function is called from a task context it may happen that a workqueue with WQ_MEM_RECLAIM bit set ends up flushing the global workqueue, this will cause a dependency issue. workqueue: WQ_MEM_RECLAIM nvme-delete-wq:nvme_delete_ctrl_work [nvme_core] is flushing !WQ_MEM_RECLAIM events:flush_cpu_slab WARNING: CPU: 37 PID: 410 at kernel/workqueue.c:2637 check_flush_dependency+0x10a/0x120 Workqueue: nvme-delete-wq nvme_delete_ctrl_work [nvme_core] RIP: 0010:check_flush_dependency+0x10a/0x120[ 453.262125] Call Trace: __flush_work.isra.0+0xbf/0x220 ? __queue_work+0x1dc/0x420 flush_all_cpus_locked+0xfb/0x120 __kmem_cache_shutdown+0x2b/0x320 kmem_cache_destroy+0x49/0x100 bioset_exit+0x143/0x190 blk_release_queue+0xb9/0x100 kobject_cleanup+0x37/0x130 nvme_fc_ctrl_free+0xc6/0x150 [nvme_fc] nvme_free_ctrl+0x1ac/0x2b0 [nvme_core] Fix this bug by creating a workqueue for the flush operation with the WQ_MEM_RECLAIM bit set.

In the Linux kernel, the following vulnerability has been resolved: arm64: topology: fix possible overflow in amu_fie_setup() cpufreq_get_hw_max_freq() returns max frequency in kHz as *unsigned int*, while freq_inv_set_max_ratio() gets passed this frequency in Hz as 'u64'. Multiplying max frequency by 1000 can potentially result in overflow -- multiplying by 1000ULL instead should avoid that... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: ti: k3-udma-private: Fix refcount leak bug in of_xudma_dev_get() We should call of_node_put() for the reference returned by of_parse_phandle() in fail path or when it is not used anymore. Here we only need to move the of_node_put() before the check.

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Harden accesses to the reset domains Accessing reset domains descriptors by the index upon the SCMI drivers requests through the SCMI reset operations interface can potentially lead to out-of-bound violations if the SCMI driver misbehave. Add an internal consistency check before any such domains descriptors accesses.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find() nf_osf_find() incorrectly returns true on mismatch, this leads to copying uninitialized memory area in nft_osf which can be used to leak stale kernel stack data to userspace.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix dcn35 8k30 Underflow/Corruption Issue [why] odm calculation is missing for pipe split policy determination and cause Underflow/Corruption issue. [how] Add the odm calculation.

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix performance regression in swap operation The patch "netfilter: ipset: fix race condition between swap/destroy and kernel side add/del/test", commit 28628fa9 fixes a race condition. But the synchronize_rcu() added to the swap function unnecessarily slows it down: it can safely be moved to destroy and use call_rcu() instead. Eric Dumazet pointed out that simply calling the destroy functions as rcu callback does not work: sets with timeout use garbage collectors which need cancelling at destroy which can wait. Therefore the destroy functions are split into two: cancelling garbage collectors safely at executing the command received by netlink and moving the remaining part only into the rcu callback.

In the Linux kernel, the following vulnerability has been resolved: pmdomain: mediatek: fix race conditions with genpd If the power domains are registered first with genpd and *after that* the driver attempts to power them on in the probe sequence, then it is possible that a race condition occurs if genpd tries to power them on in the same time. The same is valid for powering them off before unregistering them from genpd. Attempt to fix race conditions by first removing the domains from genpd and *after that* powering down domains. Also first power up the domains and *after that* register them to genpd.

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix fortify source warning while accessing Eth segment ------------[ cut here ]------------ memcpy: detected field-spanning write (size 56) of single field "eseg->inline_hdr.start" at /var/lib/dkms/mlnx-ofed-kernel/5.8/build/drivers/infiniband/hw/mlx5/wr.c:131 (size 2) WARNING: CPU: 0 PID: 293779 at /var/lib/dkms/mlnx-ofed-kernel/5.8/build/drivers/infiniband/hw/mlx5/wr.c:131 mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib] Modules linked in: 8021q garp mrp stp llc rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) ib_uverbs(OE) ib_core(OE) mlx5_core(OE) pci_hyperv_intf mlxdevm(OE) mlx_compat(OE) tls mlxfw(OE) psample nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables libcrc32c nfnetlink mst_pciconf(OE) knem(OE) vfio_pci vfio_pci_core vfio_iommu_type1 vfio iommufd irqbypass cuse nfsv3 nfs fscache netfs xfrm_user xfrm_algo ipmi_devintf ipmi_msghandler binfmt_misc crct10dif_pclmul crc32_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel sha512_ssse3 snd_pcsp aesni_intel crypto_simd cryptd snd_pcm snd_timer joydev snd soundcore input_leds serio_raw evbug nfsd auth_rpcgss nfs_acl lockd grace sch_fq_codel sunrpc drm efi_pstore ip_tables x_tables autofs4 psmouse virtio_net net_failover failover floppy [last unloaded: mlx_compat(OE)] CPU: 0 PID: 293779 Comm: ssh Tainted: G OE 6.2.0-32-generic #32~22.04.1-Ubuntu Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib] Code: 0c 01 00 a8 01 75 25 48 8b 75 a0 b9 02 00 00 00 48 c7 c2 10 5b fd c0 48 c7 c7 80 5b fd c0 c6 05 57 0c 03 00 01 e8 95 4d 93 da <0f> 0b 44 8b 4d b0 4c 8b 45 c8 48 8b 4d c0 e9 49 fb ff ff 41 0f b7 RSP: 0018:ffffb5b48478b570 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffb5b48478b628 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffb5b48478b5e8 R13: ffff963a3c609b5e R14: ffff9639c3fbd800 R15: ffffb5b480475a80 FS: 00007fc03b444c80(0000) GS:ffff963a3dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556f46bdf000 CR3: 0000000006ac6003 CR4: 00000000003706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? show_regs+0x72/0x90 ? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib] ? __warn+0x8d/0x160 ? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib] ? report_bug+0x1bb/0x1d0 ? handle_bug+0x46/0x90 ? exc_invalid_op+0x19/0x80 ? asm_exc_invalid_op+0x1b/0x20 ? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib] mlx5_ib_post_send_nodrain+0xb/0x20 [mlx5_ib] ipoib_send+0x2ec/0x770 [ib_ipoib] ipoib_start_xmit+0x5a0/0x770 [ib_ipoib] dev_hard_start_xmit+0x8e/0x1e0 ? validate_xmit_skb_list+0x4d/0x80 sch_direct_xmit+0x116/0x3a0 __dev_xmit_skb+0x1fd/0x580 __dev_queue_xmit+0x284/0x6b0 ? _raw_spin_unlock_irq+0xe/0x50 ? __flush_work.isra.0+0x20d/0x370 ? push_pseudo_header+0x17/0x40 [ib_ipoib] neigh_connected_output+0xcd/0x110 ip_finish_output2+0x179/0x480 ? __smp_call_single_queue+0x61/0xa0 __ip_finish_output+0xc3/0x190 ip_finish_output+0x2e/0xf0 ip_output+0x78/0x110 ? __pfx_ip_finish_output+0x10/0x10 ip_local_out+0x64/0x70 __ip_queue_xmit+0x18a/0x460 ip_queue_xmit+0x15/0x30 __tcp_transmit_skb+0x914/0x9c0 tcp_write_xmit+0x334/0x8d0 tcp_push_one+0x3c/0x60 tcp_sendmsg_locked+0x2e1/0xac0 tcp_sendmsg+0x2d/0x50 inet_sendmsg+0x43/0x90 sock_sendmsg+0x68/0x80 sock_write_iter+0x93/0x100 vfs_write+0x326/0x3c0 ksys_write+0xbd/0xf0 ? do_syscall_64+0x69/0x90 __x64_sys_write+0x19/0x30 do_syscall_ ---truncated---

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security During our fuzz testing of the connection and disconnection process at the RFCOMM layer, we discovered this bug. By comparing the packets from a normal connection and disconnection process with the testcase that triggered a KASAN report. We analyzed the cause of this bug as follows: 1. In the packets captured during a normal connection, the host sends a `Read Encryption Key Size` type of `HCI_CMD` packet (Command Opcode: 0x1408) to the controller to inquire the length of encryption key.After receiving this packet, the controller immediately replies with a Command Completepacket (Event Code: 0x0e) to return the Encryption Key Size. 2. In our fuzz test case, the timing of the controller's response to this packet was delayed to an unexpected point: after the RFCOMM and L2CAP layers had disconnected but before the HCI layer had disconnected. 3. After receiving the Encryption Key Size Response at the time described in point 2, the host still called the rfcomm_check_security function. However, by this time `struct l2cap_conn *conn = l2cap_pi(sk)->chan->conn;` had already been released, and when the function executed `return hci_conn_security(conn->hcon, d->sec_level, auth_type, d->out);`, specifically when accessing `conn->hcon`, a null-ptr-deref error occurred. To fix this bug, check if `sk->sk_state` is BT_CLOSED before calling rfcomm_recv_frame in rfcomm_process_rx.