CVE Database

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gem: add missing boundary check in vm_access A missing bounds check in vm_access() can lead to an out-of-bounds read or write in the adjacent memory area, since the len attribute is not validated before the memcpy later in the function, potentially hitting: [ 183.637831] BUG: unable to handle page fault for address: ffffc90000c86000 [ 183.637934] #PF: supervisor read access in kernel mode [ 183.637997] #PF: error_code(0x0000) - not-present page [ 183.638059] PGD 100000067 P4D 100000067 PUD 100258067 PMD 106341067 PTE 0 [ 183.638144] Oops: 0000 [#2] PREEMPT SMP NOPTI [ 183.638201] CPU: 3 PID: 1790 Comm: poc Tainted: G D 5.17.0-rc6-ci-drm-11296+ #1 [ 183.638298] Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake H DDR4 RVP, BIOS CNLSFWR1.R00.X208.B00.1905301319 05/30/2019 [ 183.638430] RIP: 0010:memcpy_erms+0x6/0x10 [ 183.640213] RSP: 0018:ffffc90001763d48 EFLAGS: 00010246 [ 183.641117] RAX: ffff888109c14000 RBX: ffff888111bece40 RCX: 0000000000000ffc [ 183.642029] RDX: 0000000000001000 RSI: ffffc90000c86000 RDI: ffff888109c14004 [ 183.642946] RBP: 0000000000000ffc R08: 800000000000016b R09: 0000000000000000 [ 183.643848] R10: ffffc90000c85000 R11: 0000000000000048 R12: 0000000000001000 [ 183.644742] R13: ffff888111bed190 R14: ffff888109c14000 R15: 0000000000001000 [ 183.645653] FS: 00007fe5ef807540(0000) GS:ffff88845b380000(0000) knlGS:0000000000000000 [ 183.646570] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 183.647481] CR2: ffffc90000c86000 CR3: 000000010ff02006 CR4: 00000000003706e0 [ 183.648384] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 183.649271] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 183.650142] Call Trace: [ 183.650988] <TASK> [ 183.651793] vm_access+0x1f0/0x2a0 [i915] [ 183.652726] __access_remote_vm+0x224/0x380 [ 183.653561] mem_rw.isra.0+0xf9/0x190 [ 183.654402] vfs_read+0x9d/0x1b0 [ 183.655238] ksys_read+0x63/0xe0 [ 183.656065] do_syscall_64+0x38/0xc0 [ 183.656882] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 183.657663] RIP: 0033:0x7fe5ef725142 [ 183.659351] RSP: 002b:00007ffe1e81c7e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 183.660227] RAX: ffffffffffffffda RBX: 0000557055dfb780 RCX: 00007fe5ef725142 [ 183.661104] RDX: 0000000000001000 RSI: 00007ffe1e81d880 RDI: 0000000000000005 [ 183.661972] RBP: 00007ffe1e81e890 R08: 0000000000000030 R09: 0000000000000046 [ 183.662832] R10: 0000557055dfc2e0 R11: 0000000000000246 R12: 0000557055dfb1c0 [ 183.663691] R13: 00007ffe1e81e980 R14: 0000000000000000 R15: 0000000000000000 Changes since v1: - Updated if condition with range_overflows_t [Chris Wilson] [mauld: tidy up the commit message and add Cc: stable] (cherry picked from commit 661412e301e2ca86799aa4f400d1cf0bd38c57c6)

In the Linux kernel, the following vulnerability has been resolved: crypto: ccree - Fix use after free in cc_cipher_exit() kfree_sensitive(ctx_p->user.key) will free the ctx_p->user.key. But ctx_p->user.key is still used in the next line, which will lead to a use after free. We can call kfree_sensitive() after dev_dbg() to avoid the uaf.

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: rx-macro: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes.

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: va-macro: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes.

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: rx-macro: fix accessing compander for aux AUX interpolator does not have compander, so check before accessing compander data for this. Without this checkan array of out bounds access will be made in comp_enabled[] array.

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wc938x: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes. Fix this by using enumerated items instead of integers.

In the Linux kernel, the following vulnerability has been resolved: ath11k: free peer for station when disconnect from AP for QCA6390/WCN6855 Commit b4a0f54156ac ("ath11k: move peer delete after vdev stop of station for QCA6390 and WCN6855") is to fix firmware crash by changing the WMI command sequence, but actually skip all the peer delete operation, then it lead commit 58595c9874c6 ("ath11k: Fixing dangling pointer issue upon peer delete failure") not take effect, and then happened a use-after-free warning from KASAN. because the peer->sta is not set to NULL and then used later. Change to only skip the WMI_PEER_DELETE_CMDID for QCA6390/WCN6855. log of user-after-free: [ 534.888665] BUG: KASAN: use-after-free in ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k] [ 534.888696] Read of size 8 at addr ffff8881396bb1b8 by task rtcwake/2860 [ 534.888705] CPU: 4 PID: 2860 Comm: rtcwake Kdump: loaded Tainted: G W 5.15.0-wt-ath+ #523 [ 534.888712] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021 [ 534.888716] Call Trace: [ 534.888720] <IRQ> [ 534.888726] dump_stack_lvl+0x57/0x7d [ 534.888736] print_address_description.constprop.0+0x1f/0x170 [ 534.888745] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k] [ 534.888771] kasan_report.cold+0x83/0xdf [ 534.888783] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k] [ 534.888810] ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k] [ 534.888840] ath11k_dp_rx_process_mon_status+0x529/0xa70 [ath11k] [ 534.888874] ? ath11k_dp_rx_mon_status_bufs_replenish+0x3f0/0x3f0 [ath11k] [ 534.888897] ? check_prev_add+0x20f0/0x20f0 [ 534.888922] ? __lock_acquire+0xb72/0x1870 [ 534.888937] ? find_held_lock+0x33/0x110 [ 534.888954] ath11k_dp_rx_process_mon_rings+0x297/0x520 [ath11k] [ 534.888981] ? rcu_read_unlock+0x40/0x40 [ 534.888990] ? ath11k_dp_rx_pdev_alloc+0xd90/0xd90 [ath11k] [ 534.889026] ath11k_dp_service_mon_ring+0x67/0xe0 [ath11k] [ 534.889053] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k] [ 534.889075] call_timer_fn+0x167/0x4a0 [ 534.889084] ? add_timer_on+0x3b0/0x3b0 [ 534.889103] ? lockdep_hardirqs_on_prepare.part.0+0x18c/0x370 [ 534.889117] __run_timers.part.0+0x539/0x8b0 [ 534.889123] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k] [ 534.889157] ? call_timer_fn+0x4a0/0x4a0 [ 534.889164] ? mark_lock_irq+0x1c30/0x1c30 [ 534.889173] ? clockevents_program_event+0xdd/0x280 [ 534.889189] ? mark_held_locks+0xa5/0xe0 [ 534.889203] run_timer_softirq+0x97/0x180 [ 534.889213] __do_softirq+0x276/0x86a [ 534.889230] __irq_exit_rcu+0x11c/0x180 [ 534.889238] irq_exit_rcu+0x5/0x20 [ 534.889244] sysvec_apic_timer_interrupt+0x8e/0xc0 [ 534.889251] </IRQ> [ 534.889254] <TASK> [ 534.889259] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 534.889265] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 [ 534.889271] Code: 74 24 10 e8 ea c2 bf fd 48 89 ef e8 12 53 c0 fd 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 13 a7 b5 fd 65 8b 05 cc d9 9c 5e 85 c0 74 0a 5b 5d c3 e8 a0 ee [ 534.889276] RSP: 0018:ffffc90002e5f880 EFLAGS: 00000206 [ 534.889284] RAX: 0000000000000006 RBX: 0000000000000200 RCX: ffffffff9f256f10 [ 534.889289] RDX: 0000000000000000 RSI: ffffffffa1c6e420 RDI: 0000000000000001 [ 534.889293] RBP: ffff8881095e6200 R08: 0000000000000001 R09: ffffffffa40d2b8f [ 534.889298] R10: fffffbfff481a571 R11: 0000000000000001 R12: ffff8881095e6e68 [ 534.889302] R13: ffffc90002e5f908 R14: 0000000000000246 R15: 0000000000000000 [ 534.889316] ? mark_lock+0xd0/0x14a0 [ 534.889332] klist_next+0x1d4/0x450 [ 534.889340] ? dpm_wait_for_subordinate+0x2d0/0x2d0 [ 534.889350] device_for_each_child+0xa8/0x140 [ 534.889360] ? device_remove_class_symlinks+0x1b0/0x1b0 [ 534.889370] ? __lock_release+0x4bd/0x9f0 [ 534.889378] ? dpm_suspend+0x26b/0x3f0 [ 534.889390] dpm_wait_for_subordinate+ ---truncated---

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF due to race between btf_try_get_module and load_module While working on code to populate kfunc BTF ID sets for module BTF from its initcall, I noticed that by the time the initcall is invoked, the module BTF can already be seen by userspace (and the BPF verifier). The existing btf_try_get_module calls try_module_get which only fails if mod->state == MODULE_STATE_GOING, i.e. it can increment module reference when module initcall is happening in parallel. Currently, BTF parsing happens from MODULE_STATE_COMING notifier callback. At this point, the module initcalls have not been invoked. The notifier callback parses and prepares the module BTF, allocates an ID, which publishes it to userspace, and then adds it to the btf_modules list allowing the kernel to invoke btf_try_get_module for the BTF. However, at this point, the module has not been fully initialized (i.e. its initcalls have not finished). The code in module.c can still fail and free the module, without caring for other users. However, nothing stops btf_try_get_module from succeeding between the state transition from MODULE_STATE_COMING to MODULE_STATE_LIVE. This leads to a use-after-free issue when BPF program loads successfully in the state transition, load_module's do_init_module call fails and frees the module, and BPF program fd on close calls module_put for the freed module. Future patch has test case to verify we don't regress in this area in future. There are multiple points after prepare_coming_module (in load_module) where failure can occur and module loading can return error. We illustrate and test for the race using the last point where it can practically occur (in module __init function). An illustration of the race: CPU 0 CPU 1 load_module notifier_call(MODULE_STATE_COMING) btf_parse_module btf_alloc_id // Published to userspace list_add(&btf_mod->list, btf_modules) mod->init(...) ... ^ bpf_check | check_pseudo_btf_id | btf_try_get_module | returns true | ... ... | module __init in progress return prog_fd | ... ... V if (ret < 0) free_module(mod) ... close(prog_fd) ... bpf_prog_free_deferred module_put(used_btf.mod) // use-after-free We fix this issue by setting a flag BTF_MODULE_F_LIVE, from the notifier callback when MODULE_STATE_LIVE state is reached for the module, so that we return NULL from btf_try_get_module for modules that are not fully formed. Since try_module_get already checks that module is not in MODULE_STATE_GOING state, and that is the only transition a live module can make before being removed from btf_modules list, this is enough to close the race and prevent the bug. A later selftest patch crafts the race condition artifically to verify that it has been fixed, and that verifier fails to load program (with ENXIO). Lastly, a couple of comments: 1. Even if this race didn't exist, it seems more appropriate to only access resources (ksyms and kfuncs) of a fully formed module which has been initialized completely. 2. This patch was born out of need for synchronization against module initcall for the next patch, so it is needed for correctness even without the aforementioned race condition. The BTF resources initialized by module initcall are set up once and then only looked up, so just waiting until the initcall has finished ensures correct behavior.

In the Linux kernel, the following vulnerability has been resolved: net: dsa: Avoid cross-chip syncing of VLAN filtering Changes to VLAN filtering are not applicable to cross-chip notifications. On a system like this: .-----. .-----. .-----. | sw1 +---+ sw2 +---+ sw3 | '-1-2-' '-1-2-' '-1-2-' Before this change, upon sw1p1 leaving a bridge, a call to dsa_port_vlan_filtering would also be made to sw2p1 and sw3p1. In this scenario: .---------. .-----. .-----. | sw1 +---+ sw2 +---+ sw3 | '-1-2-3-4-' '-1-2-' '-1-2-' When sw1p4 would leave a bridge, dsa_port_vlan_filtering would be called for sw2 and sw3 with a non-existing port - leading to array out-of-bounds accesses and crashes on mv88e6xxx.

In the Linux kernel, the following vulnerability has been resolved: rtw88: fix memory overrun and memory leak during hw_scan Previously we allocated less memory than actual required, overwrite to the buffer causes the mm module to complaint and raise access violation faults. Along with potential memory leaks when returned early. Fix these by passing the correct size and proper deinit flow.

In the Linux kernel, the following vulnerability has been resolved: cxl/port: Hold port reference until decoder release KASAN + DEBUG_KOBJECT_RELEASE reports a potential use-after-free in cxl_decoder_release() where it goes to reference its parent, a cxl_port, to free its id back to port->decoder_ida. BUG: KASAN: use-after-free in to_cxl_port+0x18/0x90 [cxl_core] Read of size 8 at addr ffff888119270908 by task kworker/35:2/379 CPU: 35 PID: 379 Comm: kworker/35:2 Tainted: G OE 5.17.0-rc2+ #198 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: events kobject_delayed_cleanup Call Trace: <TASK> dump_stack_lvl+0x59/0x73 print_address_description.constprop.0+0x1f/0x150 ? to_cxl_port+0x18/0x90 [cxl_core] kasan_report.cold+0x83/0xdf ? to_cxl_port+0x18/0x90 [cxl_core] to_cxl_port+0x18/0x90 [cxl_core] cxl_decoder_release+0x2a/0x60 [cxl_core] device_release+0x5f/0x100 kobject_cleanup+0x80/0x1c0 The device core only guarantees parent lifetime until all children are unregistered. If a child needs a parent to complete its ->release() callback that child needs to hold a reference to extend the lifetime of the parent.

In the Linux kernel, the following vulnerability has been resolved: drm/dp: Fix OOB read when handling Post Cursor2 register The link_status array was not large enough to read the Adjust Request Post Cursor2 register, so remove the common helper function to avoid an OOB read, found with a -Warray-bounds build: drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_get_adjust_request_post_cursor': drivers/gpu/drm/drm_dp_helper.c:59:27: error: array subscript 10 is outside array bounds of 'const u8[6]' {aka 'const unsigned char[6]'} [-Werror=array-bounds] 59 | return link_status[r - DP_LANE0_1_STATUS]; | ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/drm_dp_helper.c:147:51: note: while referencing 'link_status' 147 | u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE], | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Replace the only user of the helper with an open-coded fetch and decode, similar to drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c.

In the Linux kernel, the following vulnerability has been resolved: xsk: Fix race at socket teardown Fix a race in the xsk socket teardown code that can lead to a NULL pointer dereference splat. The current xsk unbind code in xsk_unbind_dev() starts by setting xs->state to XSK_UNBOUND, sets xs->dev to NULL and then waits for any NAPI processing to terminate using synchronize_net(). After that, the release code starts to tear down the socket state and free allocated memory. BUG: kernel NULL pointer dereference, address: 00000000000000c0 PGD 8000000932469067 P4D 8000000932469067 PUD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 25 PID: 69132 Comm: grpcpp_sync_ser Tainted: G I 5.16.0+ #2 Hardware name: Dell Inc. PowerEdge R730/0599V5, BIOS 1.2.10 03/09/2015 RIP: 0010:__xsk_sendmsg+0x2c/0x690 [...] RSP: 0018:ffffa2348bd13d50 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000040 RCX: ffff8d5fc632d258 RDX: 0000000000400000 RSI: ffffa2348bd13e10 RDI: ffff8d5fc5489800 RBP: ffffa2348bd13db0 R08: 0000000000000000 R09: 00007ffffffff000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8d5fc5489800 R13: ffff8d5fcb0f5140 R14: ffff8d5fcb0f5140 R15: 0000000000000000 FS: 00007f991cff9400(0000) GS:ffff8d6f1f700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c0 CR3: 0000000114888005 CR4: 00000000001706e0 Call Trace: <TASK> ? aa_sk_perm+0x43/0x1b0 xsk_sendmsg+0xf0/0x110 sock_sendmsg+0x65/0x70 __sys_sendto+0x113/0x190 ? debug_smp_processor_id+0x17/0x20 ? fpregs_assert_state_consistent+0x23/0x50 ? exit_to_user_mode_prepare+0xa5/0x1d0 __x64_sys_sendto+0x29/0x30 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae There are two problems with the current code. First, setting xs->dev to NULL before waiting for all users to stop using the socket is not correct. The entry to the data plane functions xsk_poll(), xsk_sendmsg(), and xsk_recvmsg() are all guarded by a test that xs->state is in the state XSK_BOUND and if not, it returns right away. But one process might have passed this test but still have not gotten to the point in which it uses xs->dev in the code. In this interim, a second process executing xsk_unbind_dev() might have set xs->dev to NULL which will lead to a crash for the first process. The solution here is just to get rid of this NULL assignment since it is not used anymore. Before commit 42fddcc7c64b ("xsk: use state member for socket synchronization"), xs->dev was the gatekeeper to admit processes into the data plane functions, but it was replaced with the state variable xs->state in the aforementioned commit. The second problem is that synchronize_net() does not wait for any process in xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() to complete, which means that the state they rely on might be cleaned up prematurely. This can happen when the notifier gets called (at driver unload for example) as it uses xsk_unbind_dev(). Solve this by extending the RCU critical region from just the ndo_xsk_wakeup to the whole functions mentioned above, so that both the test of xs->state == XSK_BOUND and the last use of any member of xs is covered by the RCU critical section. This will guarantee that when synchronize_net() completes, there will be no processes left executing xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() and state can be cleaned up safely. Note that we need to drop the RCU lock for the skb xmit path as it uses functions that might sleep. Due to this, we have to retest the xs->state after we grab the mutex that protects the skb xmit code from, among a number of things, an xsk_unbind_dev() being executed from the notifier at the same time.

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix double uncharge the mem of sk_msg If tcp_bpf_sendmsg is running during a tear down operation, psock may be freed. tcp_bpf_sendmsg() tcp_bpf_send_verdict() sk_msg_return() tcp_bpf_sendmsg_redir() unlikely(!psock)) sk_msg_free() The mem of msg has been uncharged in tcp_bpf_send_verdict() by sk_msg_return(), and would be uncharged by sk_msg_free() again. When psock is null, we can simply returning an error code, this would then trigger the sk_msg_free_nocharge in the error path of __SK_REDIRECT and would have the side effect of throwing an error up to user space. This would be a slight change in behavior from user side but would look the same as an error if the redirect on the socket threw an error. This issue can cause the following info: WARNING: CPU: 0 PID: 2136 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260 Call Trace: <TASK> __sk_destruct+0x24/0x1f0 sk_psock_destroy+0x19b/0x1c0 process_one_work+0x1b3/0x3c0 worker_thread+0x30/0x350 ? process_one_work+0x3c0/0x3c0 kthread+0xe6/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 </TASK>

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix double free during GPU reset on DC streams [Why] The issue only occurs during the GPU reset code path. We first backup the current state prior to commiting 0 streams internally from DM to DC. This state backup contains valid link encoder assignments. DC will clear the link encoder assignments as part of current state (but not the backup, since it was a copied before the commit) and free the extra stream reference it held. DC requires that the link encoder assignments remain cleared/invalid prior to commiting. Since the backup still has valid assignments we call the interface post reset to clear them. This routine also releases the extra reference that the link encoder interface held - resulting in a double free (and eventually a NULL pointer dereference). [How] We'll have to do a full DC commit anyway after GPU reset because the stream count previously went to 0. We don't need to retain the assignment that we had backed up, so just copy off of the now clean current state assignment after the reset has occcurred with the new link_enc_cfg_copy() interface.

In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Fix use after free in remove_phb_dynamic() In remove_phb_dynamic() we use &phb->io_resource, after we've called device_unregister(&host_bridge->dev). But the unregister may have freed phb, because pcibios_free_controller_deferred() is the release function for the host_bridge. If there are no outstanding references when we call device_unregister() then phb will be freed out from under us. This has gone mainly unnoticed, but with slub_debug and page_poison enabled it can lead to a crash: PID: 7574 TASK: c0000000d492cb80 CPU: 13 COMMAND: "drmgr" #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc #1 [c0000000e4f075d0] oops_end at c000000000029608 #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4 #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8 #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30 Data SLB Access [380] exception frame: R0: c000000000167250 R1: c0000000e4f07a00 R2: c000000002a46100 R3: c000000002b39ce8 R4: 00000000000000c0 R5: 00000000000000a9 R6: 3894674d000000c0 R7: 0000000000000000 R8: 00000000000000ff R9: 0000000000000100 R10: 6b6b6b6b6b6b6b6b R11: 0000000000008000 R12: c00000000023da80 R13: c0000009ffd38b00 R14: 0000000000000000 R15: 000000011c87f0f0 R16: 0000000000000006 R17: 0000000000000003 R18: 0000000000000002 R19: 0000000000000004 R20: 0000000000000005 R21: 000000011c87ede8 R22: 000000011c87c5a8 R23: 000000011c87d3a0 R24: 0000000000000000 R25: 0000000000000001 R26: c0000000e4f07cc8 R27: c00000004d1cc400 R28: c0080000031d00e8 R29: c00000004d23d800 R30: c00000004d1d2400 R31: c00000004d1d2540 NIP: c000000000167258 MSR: 8000000000009033 OR3: c000000000e9f474 CTR: 0000000000000000 LR: c000000000167250 XER: 0000000020040003 CCR: 0000000024088420 MQ: 0000000000000000 DAR: 6b6b6b6b6b6b6ba3 DSISR: c0000000e4f07920 Syscall Result: fffffffffffffff2 [NIP : release_resource+56] [LR : release_resource+48] #5 [c0000000e4f07a00] release_resource at c000000000167258 (unreliable) #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648 #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io] #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io] #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504 #11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868 #12 [c0000000e4f07c70] new_sync_write at c00000000054339c #13 [c0000000e4f07d10] vfs_write at c000000000546624 #14 [c0000000e4f07d60] ksys_write at c0000000005469f4 #15 [c0000000e4f07db0] system_call_exception at c000000000030840 #16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168 To avoid it, we can take a reference to the host_bridge->dev until we're done using phb. Then when we drop the reference the phb will be freed.

In the Linux kernel, the following vulnerability has been resolved: clk: visconti: prevent array overflow in visconti_clk_register_gates() This code was using -1 to represent that there was no reset function. Unfortunately, the -1 was stored in u8 so the if (clks[i].rs_id >= 0) condition was always true. This lead to an out of bounds access in visconti_clk_register_gates().

In the Linux kernel, the following vulnerability has been resolved: net: hns3: add vlan list lock to protect vlan list When adding port base VLAN, vf VLAN need to remove from HW and modify the vlan state in vf VLAN list as false. If the periodicity task is freeing the same node, it may cause "use after free" error. This patch adds a vlan list lock to protect the vlan list.

In the Linux kernel, the following vulnerability has been resolved: block, bfq: don't move oom_bfqq Our test report a UAF: [ 2073.019181] ================================================================== [ 2073.019188] BUG: KASAN: use-after-free in __bfq_put_async_bfqq+0xa0/0x168 [ 2073.019191] Write of size 8 at addr ffff8000ccf64128 by task rmmod/72584 [ 2073.019192] [ 2073.019196] CPU: 0 PID: 72584 Comm: rmmod Kdump: loaded Not tainted 4.19.90-yk #5 [ 2073.019198] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 [ 2073.019200] Call trace: [ 2073.019203] dump_backtrace+0x0/0x310 [ 2073.019206] show_stack+0x28/0x38 [ 2073.019210] dump_stack+0xec/0x15c [ 2073.019216] print_address_description+0x68/0x2d0 [ 2073.019220] kasan_report+0x238/0x2f0 [ 2073.019224] __asan_store8+0x88/0xb0 [ 2073.019229] __bfq_put_async_bfqq+0xa0/0x168 [ 2073.019233] bfq_put_async_queues+0xbc/0x208 [ 2073.019236] bfq_pd_offline+0x178/0x238 [ 2073.019240] blkcg_deactivate_policy+0x1f0/0x420 [ 2073.019244] bfq_exit_queue+0x128/0x178 [ 2073.019249] blk_mq_exit_sched+0x12c/0x160 [ 2073.019252] elevator_exit+0xc8/0xd0 [ 2073.019256] blk_exit_queue+0x50/0x88 [ 2073.019259] blk_cleanup_queue+0x228/0x3d8 [ 2073.019267] null_del_dev+0xfc/0x1e0 [null_blk] [ 2073.019274] null_exit+0x90/0x114 [null_blk] [ 2073.019278] __arm64_sys_delete_module+0x358/0x5a0 [ 2073.019282] el0_svc_common+0xc8/0x320 [ 2073.019287] el0_svc_handler+0xf8/0x160 [ 2073.019290] el0_svc+0x10/0x218 [ 2073.019291] [ 2073.019294] Allocated by task 14163: [ 2073.019301] kasan_kmalloc+0xe0/0x190 [ 2073.019305] kmem_cache_alloc_node_trace+0x1cc/0x418 [ 2073.019308] bfq_pd_alloc+0x54/0x118 [ 2073.019313] blkcg_activate_policy+0x250/0x460 [ 2073.019317] bfq_create_group_hierarchy+0x38/0x110 [ 2073.019321] bfq_init_queue+0x6d0/0x948 [ 2073.019325] blk_mq_init_sched+0x1d8/0x390 [ 2073.019330] elevator_switch_mq+0x88/0x170 [ 2073.019334] elevator_switch+0x140/0x270 [ 2073.019338] elv_iosched_store+0x1a4/0x2a0 [ 2073.019342] queue_attr_store+0x90/0xe0 [ 2073.019348] sysfs_kf_write+0xa8/0xe8 [ 2073.019351] kernfs_fop_write+0x1f8/0x378 [ 2073.019359] __vfs_write+0xe0/0x360 [ 2073.019363] vfs_write+0xf0/0x270 [ 2073.019367] ksys_write+0xdc/0x1b8 [ 2073.019371] __arm64_sys_write+0x50/0x60 [ 2073.019375] el0_svc_common+0xc8/0x320 [ 2073.019380] el0_svc_handler+0xf8/0x160 [ 2073.019383] el0_svc+0x10/0x218 [ 2073.019385] [ 2073.019387] Freed by task 72584: [ 2073.019391] __kasan_slab_free+0x120/0x228 [ 2073.019394] kasan_slab_free+0x10/0x18 [ 2073.019397] kfree+0x94/0x368 [ 2073.019400] bfqg_put+0x64/0xb0 [ 2073.019404] bfqg_and_blkg_put+0x90/0xb0 [ 2073.019408] bfq_put_queue+0x220/0x228 [ 2073.019413] __bfq_put_async_bfqq+0x98/0x168 [ 2073.019416] bfq_put_async_queues+0xbc/0x208 [ 2073.019420] bfq_pd_offline+0x178/0x238 [ 2073.019424] blkcg_deactivate_policy+0x1f0/0x420 [ 2073.019429] bfq_exit_queue+0x128/0x178 [ 2073.019433] blk_mq_exit_sched+0x12c/0x160 [ 2073.019437] elevator_exit+0xc8/0xd0 [ 2073.019440] blk_exit_queue+0x50/0x88 [ 2073.019443] blk_cleanup_queue+0x228/0x3d8 [ 2073.019451] null_del_dev+0xfc/0x1e0 [null_blk] [ 2073.019459] null_exit+0x90/0x114 [null_blk] [ 2073.019462] __arm64_sys_delete_module+0x358/0x5a0 [ 2073.019467] el0_svc_common+0xc8/0x320 [ 2073.019471] el0_svc_handler+0xf8/0x160 [ 2073.019474] el0_svc+0x10/0x218 [ 2073.019475] [ 2073.019479] The buggy address belongs to the object at ffff8000ccf63f00 which belongs to the cache kmalloc-1024 of size 1024 [ 2073.019484] The buggy address is located 552 bytes inside of 1024-byte region [ffff8000ccf63f00, ffff8000ccf64300) [ 2073.019486] The buggy address belongs to the page: [ 2073.019492] page:ffff7e000333d800 count:1 mapcount:0 mapping:ffff8000c0003a00 index:0x0 compound_mapcount: 0 [ 2073.020123] flags: 0x7ffff0000008100(slab|head) [ 2073.020403] raw: 07ffff0000008100 ffff7e0003334c08 ffff7e00001f5a08 ffff8000c0003a00 [ 2073.020409] ra ---truncated---

In the Linux kernel, the following vulnerability has been resolved: memstick/mspro_block: fix handling of read-only devices Use set_disk_ro to propagate the read-only state to the block layer instead of checking for it in ->open and leaking a reference in case of a read-only device.

In the Linux kernel, the following vulnerability has been resolved: bfq: fix use-after-free in bfq_dispatch_request KASAN reports a use-after-free report when doing normal scsi-mq test [69832.239032] ================================================================== [69832.241810] BUG: KASAN: use-after-free in bfq_dispatch_request+0x1045/0x44b0 [69832.243267] Read of size 8 at addr ffff88802622ba88 by task kworker/3:1H/155 [69832.244656] [69832.245007] CPU: 3 PID: 155 Comm: kworker/3:1H Not tainted 5.10.0-10295-g576c6382529e #8 [69832.246626] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [69832.249069] Workqueue: kblockd blk_mq_run_work_fn [69832.250022] Call Trace: [69832.250541] dump_stack+0x9b/0xce [69832.251232] ? bfq_dispatch_request+0x1045/0x44b0 [69832.252243] print_address_description.constprop.6+0x3e/0x60 [69832.253381] ? __cpuidle_text_end+0x5/0x5 [69832.254211] ? vprintk_func+0x6b/0x120 [69832.254994] ? bfq_dispatch_request+0x1045/0x44b0 [69832.255952] ? bfq_dispatch_request+0x1045/0x44b0 [69832.256914] kasan_report.cold.9+0x22/0x3a [69832.257753] ? bfq_dispatch_request+0x1045/0x44b0 [69832.258755] check_memory_region+0x1c1/0x1e0 [69832.260248] bfq_dispatch_request+0x1045/0x44b0 [69832.261181] ? bfq_bfqq_expire+0x2440/0x2440 [69832.262032] ? blk_mq_delay_run_hw_queues+0xf9/0x170 [69832.263022] __blk_mq_do_dispatch_sched+0x52f/0x830 [69832.264011] ? blk_mq_sched_request_inserted+0x100/0x100 [69832.265101] __blk_mq_sched_dispatch_requests+0x398/0x4f0 [69832.266206] ? blk_mq_do_dispatch_ctx+0x570/0x570 [69832.267147] ? __switch_to+0x5f4/0xee0 [69832.267898] blk_mq_sched_dispatch_requests+0xdf/0x140 [69832.268946] __blk_mq_run_hw_queue+0xc0/0x270 [69832.269840] blk_mq_run_work_fn+0x51/0x60 [69832.278170] process_one_work+0x6d4/0xfe0 [69832.278984] worker_thread+0x91/0xc80 [69832.279726] ? __kthread_parkme+0xb0/0x110 [69832.280554] ? process_one_work+0xfe0/0xfe0 [69832.281414] kthread+0x32d/0x3f0 [69832.282082] ? kthread_park+0x170/0x170 [69832.282849] ret_from_fork+0x1f/0x30 [69832.283573] [69832.283886] Allocated by task 7725: [69832.284599] kasan_save_stack+0x19/0x40 [69832.285385] __kasan_kmalloc.constprop.2+0xc1/0xd0 [69832.286350] kmem_cache_alloc_node+0x13f/0x460 [69832.287237] bfq_get_queue+0x3d4/0x1140 [69832.287993] bfq_get_bfqq_handle_split+0x103/0x510 [69832.289015] bfq_init_rq+0x337/0x2d50 [69832.289749] bfq_insert_requests+0x304/0x4e10 [69832.290634] blk_mq_sched_insert_requests+0x13e/0x390 [69832.291629] blk_mq_flush_plug_list+0x4b4/0x760 [69832.292538] blk_flush_plug_list+0x2c5/0x480 [69832.293392] io_schedule_prepare+0xb2/0xd0 [69832.294209] io_schedule_timeout+0x13/0x80 [69832.295014] wait_for_common_io.constprop.1+0x13c/0x270 [69832.296137] submit_bio_wait+0x103/0x1a0 [69832.296932] blkdev_issue_discard+0xe6/0x160 [69832.297794] blk_ioctl_discard+0x219/0x290 [69832.298614] blkdev_common_ioctl+0x50a/0x1750 [69832.304715] blkdev_ioctl+0x470/0x600 [69832.305474] block_ioctl+0xde/0x120 [69832.306232] vfs_ioctl+0x6c/0xc0 [69832.306877] __se_sys_ioctl+0x90/0xa0 [69832.307629] do_syscall_64+0x2d/0x40 [69832.308362] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [69832.309382] [69832.309701] Freed by task 155: [69832.310328] kasan_save_stack+0x19/0x40 [69832.311121] kasan_set_track+0x1c/0x30 [69832.311868] kasan_set_free_info+0x1b/0x30 [69832.312699] __kasan_slab_free+0x111/0x160 [69832.313524] kmem_cache_free+0x94/0x460 [69832.314367] bfq_put_queue+0x582/0x940 [69832.315112] __bfq_bfqd_reset_in_service+0x166/0x1d0 [69832.317275] bfq_bfqq_expire+0xb27/0x2440 [69832.318084] bfq_dispatch_request+0x697/0x44b0 [69832.318991] __blk_mq_do_dispatch_sched+0x52f/0x830 [69832.319984] __blk_mq_sched_dispatch_requests+0x398/0x4f0 [69832.321087] blk_mq_sched_dispatch_requests+0xdf/0x140 [69832.322225] __blk_mq_run_hw_queue+0xc0/0x270 [69832.323114] blk_mq_run_work_fn+0x51/0x6 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: ext4: fix ext4_mb_mark_bb() with flex_bg with fast_commit In case of flex_bg feature (which is by default enabled), extents for any given inode might span across blocks from two different block group. ext4_mb_mark_bb() only reads the buffer_head of block bitmap once for the starting block group, but it fails to read it again when the extent length boundary overflows to another block group. Then in this below loop it accesses memory beyond the block group bitmap buffer_head and results into a data abort. for (i = 0; i < clen; i++) if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state) already++; This patch adds this functionality for checking block group boundary in ext4_mb_mark_bb() and update the buffer_head(bitmap_bh) for every different block group. w/o this patch, I was easily able to hit a data access abort using Power platform. <...> [ 74.327662] EXT4-fs error (device loop3): ext4_mb_generate_buddy:1141: group 11, block bitmap and bg descriptor inconsistent: 21248 vs 23294 free clusters [ 74.533214] EXT4-fs (loop3): shut down requested (2) [ 74.536705] Aborting journal on device loop3-8. [ 74.702705] BUG: Unable to handle kernel data access on read at 0xc00000005e980000 [ 74.703727] Faulting instruction address: 0xc0000000007bffb8 cpu 0xd: Vector: 300 (Data Access) at [c000000015db7060] pc: c0000000007bffb8: ext4_mb_mark_bb+0x198/0x5a0 lr: c0000000007bfeec: ext4_mb_mark_bb+0xcc/0x5a0 sp: c000000015db7300 msr: 800000000280b033 dar: c00000005e980000 dsisr: 40000000 current = 0xc000000027af6880 paca = 0xc00000003ffd5200 irqmask: 0x03 irq_happened: 0x01 pid = 5167, comm = mount <...> enter ? for help [c000000015db7380] c000000000782708 ext4_ext_clear_bb+0x378/0x410 [c000000015db7400] c000000000813f14 ext4_fc_replay+0x1794/0x2000 [c000000015db7580] c000000000833f7c do_one_pass+0xe9c/0x12a0 [c000000015db7710] c000000000834504 jbd2_journal_recover+0x184/0x2d0 [c000000015db77c0] c000000000841398 jbd2_journal_load+0x188/0x4a0 [c000000015db7880] c000000000804de8 ext4_fill_super+0x2638/0x3e10 [c000000015db7a40] c0000000005f8404 get_tree_bdev+0x2b4/0x350 [c000000015db7ae0] c0000000007ef058 ext4_get_tree+0x28/0x40 [c000000015db7b00] c0000000005f6344 vfs_get_tree+0x44/0x100 [c000000015db7b70] c00000000063c408 path_mount+0xdd8/0xe70 [c000000015db7c40] c00000000063c8f0 sys_mount+0x450/0x550 [c000000015db7d50] c000000000035770 system_call_exception+0x4a0/0x4e0 [c000000015db7e10] c00000000000c74c system_call_common+0xec/0x250

In the Linux kernel, the following vulnerability has been resolved: parisc: Fix non-access data TLB cache flush faults When a page is not present, we get non-access data TLB faults from the fdc and fic instructions in flush_user_dcache_range_asm and flush_user_icache_range_asm. When these occur, the cache line is not invalidated and potentially we get memory corruption. The problem was hidden by the nullification of the flush instructions. These faults also affect performance. With pa8800/pa8900 processors, there will be 32 faults per 4 KB page since the cache line is 128 bytes. There will be more faults with earlier processors. The problem is fixed by using flush_cache_pages(). It does the flush using a tmp alias mapping. The flush_cache_pages() call in flush_cache_range() flushed too large a range. V2: Remove unnecessary preempt_disable() and preempt_enable() calls.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on curseg->alloc_type As Wenqing Liu reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215657 - Overview UBSAN: array-index-out-of-bounds in fs/f2fs/segment.c:3460:2 when mount and operate a corrupted image - Reproduce tested on kernel 5.17-rc4, 5.17-rc6 1. mkdir test_crash 2. cd test_crash 3. unzip tmp2.zip 4. mkdir mnt 5. ./single_test.sh f2fs 2 - Kernel dump [ 46.434454] loop0: detected capacity change from 0 to 131072 [ 46.529839] F2FS-fs (loop0): Mounted with checkpoint version = 7548c2d9 [ 46.738319] ================================================================================ [ 46.738412] UBSAN: array-index-out-of-bounds in fs/f2fs/segment.c:3460:2 [ 46.738475] index 231 is out of range for type 'unsigned int [2]' [ 46.738539] CPU: 2 PID: 939 Comm: umount Not tainted 5.17.0-rc6 #1 [ 46.738547] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 46.738551] Call Trace: [ 46.738556] <TASK> [ 46.738563] dump_stack_lvl+0x47/0x5c [ 46.738581] ubsan_epilogue+0x5/0x50 [ 46.738592] __ubsan_handle_out_of_bounds+0x68/0x80 [ 46.738604] f2fs_allocate_data_block+0xdff/0xe60 [f2fs] [ 46.738819] do_write_page+0xef/0x210 [f2fs] [ 46.738934] f2fs_do_write_node_page+0x3f/0x80 [f2fs] [ 46.739038] __write_node_page+0x2b7/0x920 [f2fs] [ 46.739162] f2fs_sync_node_pages+0x943/0xb00 [f2fs] [ 46.739293] f2fs_write_checkpoint+0x7bb/0x1030 [f2fs] [ 46.739405] kill_f2fs_super+0x125/0x150 [f2fs] [ 46.739507] deactivate_locked_super+0x60/0xc0 [ 46.739517] deactivate_super+0x70/0xb0 [ 46.739524] cleanup_mnt+0x11a/0x200 [ 46.739532] __cleanup_mnt+0x16/0x20 [ 46.739538] task_work_run+0x67/0xa0 [ 46.739547] exit_to_user_mode_prepare+0x18c/0x1a0 [ 46.739559] syscall_exit_to_user_mode+0x26/0x40 [ 46.739568] do_syscall_64+0x46/0xb0 [ 46.739584] entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is we missed to do sanity check on curseg->alloc_type, result in out-of-bound accessing on sbi->block_count[] array, fix it.

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not clean up repair bio if submit fails The submit helper will always run bio_endio() on the bio if it fails to submit, so cleaning up the bio just leads to a variety of use-after-free and NULL pointer dereference bugs because we race with the endio function that is cleaning up the bio. Instead just return BLK_STS_OK as the repair function has to continue to process the rest of the pages, and the endio for the repair bio will do the appropriate cleanup for the page that it was given.

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not double complete bio on errors during compressed reads I hit some weird panics while fixing up the error handling from btrfs_lookup_bio_sums(). Turns out the compression path will complete the bio we use if we set up any of the compression bios and then return an error, and then btrfs_submit_data_bio() will also call bio_endio() on the bio. Fix this by making btrfs_submit_compressed_read() responsible for calling bio_endio() on the bio if there are any errors. Currently it was only doing it if we created the compression bios, otherwise it was depending on btrfs_submit_data_bio() to do the right thing. This creates the above problem, so fix up btrfs_submit_compressed_read() to always call bio_endio() in case of an error, and then simply return from btrfs_submit_data_bio() if we had to call btrfs_submit_compressed_read().

In the Linux kernel, the following vulnerability has been resolved: media: imx-jpeg: fix a bug of accessing array out of bounds When error occurs in parsing jpeg, the slot isn't acquired yet, it may be the default value MXC_MAX_SLOTS. If the driver access the slot using the incorrect slot number, it will access array out of bounds. The result is the driver will change num_domains, which follows slot_data in struct mxc_jpeg_dev. Then the driver won't detach the pm domain at rmmod, which will lead to kernel panic when trying to insmod again.

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: sm712fb: Fix crash in smtcfb_write() When the sm712fb driver writes three bytes to the framebuffer, the driver will crash: BUG: unable to handle page fault for address: ffffc90001ffffff RIP: 0010:smtcfb_write+0x454/0x5b0 Call Trace: vfs_write+0x291/0xd60 ? do_sys_openat2+0x27d/0x350 ? __fget_light+0x54/0x340 ksys_write+0xce/0x190 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Fix it by removing the open-coded endianness fixup-code.

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix crash during module load unload test During purex packet handling the driver was incorrectly freeing a pre-allocated structure. Fix this by skipping that entry. System crashed with the following stack during a module unload test. Call Trace: sbitmap_init_node+0x7f/0x1e0 sbitmap_queue_init_node+0x24/0x150 blk_mq_init_bitmaps+0x3d/0xa0 blk_mq_init_tags+0x68/0x90 blk_mq_alloc_map_and_rqs+0x44/0x120 blk_mq_alloc_set_map_and_rqs+0x63/0x150 blk_mq_alloc_tag_set+0x11b/0x230 scsi_add_host_with_dma.cold+0x3f/0x245 qla2x00_probe_one+0xd5a/0x1b80 [qla2xxx] Call Trace with slub_debug and debug kernel: kasan_report_invalid_free+0x50/0x80 __kasan_slab_free+0x137/0x150 slab_free_freelist_hook+0xc6/0x190 kfree+0xe8/0x2e0 qla2x00_free_device+0x3bb/0x5d0 [qla2xxx] qla2x00_remove_one+0x668/0xcf0 [qla2xxx]

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Implement ref count for SRB The timeout handler and the done function are racing. When qla2x00_async_iocb_timeout() starts to run it can be preempted by the normal response path (via the firmware?). qla24xx_async_gpsc_sp_done() releases the SRB unconditionally. When scheduling back to qla2x00_async_iocb_timeout() qla24xx_async_abort_cmd() will access an freed sp->qpair pointer: qla2xxx [0000:83:00.0]-2871:0: Async-gpsc timeout - hdl=63d portid=234500 50:06:0e:80:08:77:b6:21. qla2xxx [0000:83:00.0]-2853:0: Async done-gpsc res 0, WWPN 50:06:0e:80:08:77:b6:21 qla2xxx [0000:83:00.0]-2854:0: Async-gpsc OUT WWPN 20:45:00:27:f8:75:33:00 speeds=2c00 speed=0400. qla2xxx [0000:83:00.0]-28d8:0: qla24xx_handle_gpsc_event 50:06:0e:80:08:77:b6:21 DS 7 LS 6 rc 0 login 1|1 rscn 1|0 lid 5 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: qla24xx_async_abort_cmd+0x1b/0x1c0 [qla2xxx] Obvious solution to this is to introduce a reference counter. One reference is taken for the normal code path (the 'good' case) and one for the timeout path. As we always race between the normal good case and the timeout/abort handler we need to serialize it. Also we cannot assume any order between the handlers. Since this is slow path we can use proper synchronization via locks. When we are able to cancel a timer (del_timer returns 1) we know there can't be any error handling in progress because the timeout handler hasn't expired yet, thus we can safely decrement the refcounter by one. If we are not able to cancel the timer, we know an abort handler is running. We have to make sure we call sp->done() in the abort handlers before calling kref_put().