Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: drm/i915: Fix a memory leak with reused mmap_offset drm_vma_node_allow() and drm_vma_node_revoke() should be called in balanced pairs. We call drm_vma_node_allow() once per-file everytime a user calls mmap_offset, but only call drm_vma_node_revoke once per-file on each mmap_offset. As the mmap_offset is reused by the client, the per-file vm_count may remain non-zero and the rbtree leaked. Call drm_vma_node_allow_once() instead to prevent that memory leak.Show less

In the Linux kernel, the following vulnerability has been resolved: netlink: prevent potential spectre v1 gadgets Most netlink attributes are parsed and validated from __nla_validate_parse() or validate_nla() u16 type = nla_type(nla); if (type == 0 || type > maxtype) { /* error or continue */ } @type is then used as an array index and can be used as a Spectre v1 gadget. array_index_nospec() can be used to prevent leaking content of kernel memory to malicious users. This should take care of vast majority of netlink uses, but an audit is needed to take care of others where validation is not yet centralized in core netlink functions.Show less

In the Linux kernel, the following vulnerability has been resolved: net: fix UaF in netns ops registration error path If net_assign_generic() fails, the current error path in ops_init() tries to clear the gen pointer slot. Anyway, in such error path, the gen pointer itself has not been modified yet, and the existing and accessed one is smaller than the accessed index, causing an out-of-bounds error: BUG: KASAN: slab-out-of-bounds in ops_init+0x2de/0x320 Write of size 8 at addr ffff888109124978 by task modprobe/1018 CPU: 2 PID: 1018 Comm: modprobe Not tainted 6.2.0-rc2.mptcp_ae5ac65fbed5+ #1641 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6a/0x9f print_address_description.constprop.0+0x86/0x2b5 print_report+0x11b/0x1fb kasan_report+0x87/0xc0 ops_init+0x2de/0x320 register_pernet_operations+0x2e4/0x750 register_pernet_subsys+0x24/0x40 tcf_register_action+0x9f/0x560 do_one_initcall+0xf9/0x570 do_init_module+0x190/0x650 load_module+0x1fa5/0x23c0 __do_sys_finit_module+0x10d/0x1b0 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f42518f778d Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d cb 56 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007fff96869688 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 00005568ef7f7c90 RCX: 00007f42518f778d RDX: 0000000000000000 RSI: 00005568ef41d796 RDI: 0000000000000003 RBP: 00005568ef41d796 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00005568ef7f7d30 R14: 0000000000040000 R15: 0000000000000000 </TASK> This change addresses the issue by skipping the gen pointer de-reference in the mentioned error-path. Found by code inspection and verified with explicit error injection on a kasan-enabled kernel.Show less

In the Linux kernel, the following vulnerability has been resolved: net: fec: Use page_pool_put_full_page when freeing rx buffers The page_pool_release_page was used when freeing rx buffers, and this function just unmaps the page (if mapped) and does not recycle the page. So after hundreds of down/up the eth0, the system will out of memory. For more details, please refer to the following reproduce steps and bug logs. To solve this issue and refer to the doc of page pool, the page_pool_put_full_page should be used to replace page_pool_release_page. Because this API will try to recycle the page if the page refcnt equal to 1. After testing 20000 times, the issue can not be reproduced anymore (about testing 391 times the issue will occur on i.MX8MN-EVK before). Reproduce steps: Create the test script and run the script. The script content is as follows: LOOPS=20000 i=1 while [ $i -le $LOOPS ] do echo "TINFO:ENET $curface up and down test $i times" org_macaddr=$(cat /sys/class/net/eth0/address) ifconfig eth0 down ifconfig eth0 hw ether $org_macaddr up i=$(expr $i + 1) done sleep 5 if cat /sys/class/net/eth0/operstate | grep 'up';then echo "TEST PASS" else echo "TEST FAIL" fi Bug detail logs: TINFO:ENET up and down test 391 times [ 850.471205] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL) [ 853.535318] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 853.541694] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx [ 870.590531] page_pool_release_retry() stalled pool shutdown 199 inflight 60 sec [ 931.006557] page_pool_release_retry() stalled pool shutdown 199 inflight 120 sec TINFO:ENET up and down test 392 times [ 991.426544] page_pool_release_retry() stalled pool shutdown 192 inflight 181 sec [ 1051.838531] page_pool_release_retry() stalled pool shutdown 170 inflight 241 sec [ 1093.751217] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL) [ 1096.446520] page_pool_release_retry() stalled pool shutdown 308 inflight 60 sec [ 1096.831245] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx [ 1096.839092] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 1112.254526] page_pool_release_retry() stalled pool shutdown 103 inflight 302 sec [ 1156.862533] page_pool_release_retry() stalled pool shutdown 308 inflight 120 sec [ 1172.674516] page_pool_release_retry() stalled pool shutdown 103 inflight 362 sec [ 1217.278532] page_pool_release_retry() stalled pool shutdown 308 inflight 181 sec TINFO:ENET up and down test 393 times [ 1233.086535] page_pool_release_retry() stalled pool shutdown 103 inflight 422 sec [ 1277.698513] page_pool_release_retry() stalled pool shutdown 308 inflight 241 sec [ 1293.502525] page_pool_release_retry() stalled pool shutdown 86 inflight 483 sec [ 1338.110518] page_pool_release_retry() stalled pool shutdown 308 inflight 302 sec [ 1353.918540] page_pool_release_retry() stalled pool shutdown 32 inflight 543 sec [ 1361.179205] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL) [ 1364.255298] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx [ 1364.263189] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 1371.998532] page_pool_release_retry() stalled pool shutdown 310 inflight 60 sec [ 1398.530542] page_pool_release_retry() stalled pool shutdown 308 inflight 362 sec [ 1414.334539] page_pool_release_retry() stalled pool shutdown 16 inflight 604 sec [ 1432.414520] page_pool_release_retry() stalled pool shutdown 310 inflight 120 sec [ 1458.942523] page_pool_release_retry() stalled pool shutdown 308 inflight 422 sec [ 1474.750521] page_pool_release_retry() stalled pool shutdown 16 inflight 664 sec TINFO:ENET up and down test 394 times [ 1492.8305 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() if (!type) continue; if (type > RTAX_MAX) return -EINVAL; ... metrics[type - 1] = val; @type being used as an array index, we need to prevent cpu speculation or risk leaking kernel memory content.Show less

In the Linux kernel, the following vulnerability has been resolved: ipv4: prevent potential spectre v1 gadget in fib_metrics_match() if (!type) continue; if (type > RTAX_MAX) return false; ... fi_val = fi->fib_metrics->metrics[type - 1]; @type being used as an array index, we need to prevent cpu speculation or risk leaking kernel memory content.Show less

In the Linux kernel, the following vulnerability has been resolved: riscv/kprobe: Fix instruction simulation of JALR Set kprobe at 'jalr 1140(ra)' of vfs_write results in the following crash: [ 32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170 [ 32.093115] Oops [#1] [ 32.093251] Modules linked in: [ 32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty #16 [ 32.093985] Hardware name: riscv-virtio,qemu (DT) [ 32.094280] epc : ksys_read+0x88/0xd6 [ 32.094855] ra : ksys_read+0xc0/0xd6 [ 32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0 [ 32.095227] gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80 [ 32.095500] t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60 [ 32.095716] s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708 [ 32.095921] a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300 [ 32.096171] a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff [ 32.096411] s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170 [ 32.096638] s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030 [ 32.096865] s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410 [ 32.097092] s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c [ 32.097317] t5 : ffffffff8000c29c t6 : ffffffff800dbc54 [ 32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d [ 32.098011] [<ffffffff801cdb72>] ksys_write+0x6c/0xd6 [ 32.098222] [<ffffffff801cdc06>] sys_write+0x2a/0x38 [ 32.098405] [<ffffffff80003c76>] ret_from_syscall+0x0/0x2 Since the rs1 and rd might be the same one, such as 'jalr 1140(ra)', hence it requires obtaining the target address from rs1 followed by updating rd. [Palmer: Pick Guo's cleanup]Show less

In the Linux kernel, the following vulnerability has been resolved: acpi: Fix suspend with Xen PV Commit f1e525009493 ("x86/boot: Skip realmode init code when running as Xen PV guest") missed one code path accessing real_mode_header, leading to dereferencing NULL when suspending the system under Xen: [ 348.284004] PM: suspend entry (deep) [ 348.289532] Filesystems sync: 0.005 seconds [ 348.291545] Freezing user space processes ... (elapsed 0.000 seconds) done. [ 348.292457] OOM killer disabled. [ 348.292462] Freezing remaining freezable tasks ... (elapsed 0.104 seconds) done. [ 348.396612] printk: Suspending console(s) (use no_console_suspend to debug) [ 348.749228] PM: suspend devices took 0.352 seconds [ 348.769713] ACPI: EC: interrupt blocked [ 348.816077] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 348.816080] #PF: supervisor read access in kernel mode [ 348.816081] #PF: error_code(0x0000) - not-present page [ 348.816083] PGD 0 P4D 0 [ 348.816086] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 348.816089] CPU: 0 PID: 6764 Comm: systemd-sleep Not tainted 6.1.3-1.fc32.qubes.x86_64 #1 [ 348.816092] Hardware name: Star Labs StarBook/StarBook, BIOS 8.01 07/03/2022 [ 348.816093] RIP: e030:acpi_get_wakeup_address+0xc/0x20 Fix that by adding an optional acpi callback allowing to skip setting the wakeup address, as in the Xen PV case this will be handled by the hypervisor anyway.Show less

In the Linux kernel, the following vulnerability has been resolved: x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL Baoquan reported that after triggering a crash the subsequent crash-kernel fails to boot about half of the time. It triggers a NULL pointer dereference in the periodic tick code. This happens because the legacy timer interrupt (IRQ0) is resent in software which happens in soft interrupt (tasklet) context. In this context get_irq_regs() returns NULL which leads to the NULL pointer dereference. The reason for the resend is a spurious APIC interrupt on the IRQ0 vector which is captured and leads to a resend when the legacy timer interrupt is enabled. This is wrong because the legacy PIC interrupts are level triggered and therefore should never be resent in software, but nothing ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not know about their trigger type. Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.Show less

In the Linux kernel, the following vulnerability has been resolved: bpf: Skip task with pid=1 in send_signal_common() The following kernel panic can be triggered when a task with pid=1 attaches a prog that attempts to send killing signal to itself, also see [1] for more details: Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b CPU: 3 PID: 1 Comm: systemd Not tainted 6.1.0-09652-g59fe41b5255f #148 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x100/0x178 lib/dump_stack.c:106 panic+0x2c4/0x60f kernel/panic.c:275 do_exit.cold+0x63/0xe4 kernel/exit.c:789 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x2460/0x2600 kernel/signal.c:2858 arch_do_signal_or_restart+0x78/0x5d0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd So skip task with pid=1 in bpf_send_signal_common() to avoid the panic. [1] https://lore.kernel.org/bpf/20221222043507.33037-1-sunhao.th@gmail.comShow less

In the Linux kernel, the following vulnerability has been resolved: net: fix NULL pointer in skb_segment_list Commit 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.") introduced UDP listifyed GRO. The segmentation relies on frag_list being untouched when passing through the network stack. This assumption can be broken sometimes, where frag_list itself gets pulled into linear area, leaving frag_list being NULL. When this happens it can trigger following NULL pointer dereference, and panic the kernel. Reverse the test condition should fix it. [19185.577801][ C1] BUG: kernel NULL pointer dereference, address: ... [19185.663775][ C1] RIP: 0010:skb_segment_list+0x1cc/0x390 ... [19185.834644][ C1] Call Trace: [19185.841730][ C1] <TASK> [19185.848563][ C1] __udp_gso_segment+0x33e/0x510 [19185.857370][ C1] inet_gso_segment+0x15b/0x3e0 [19185.866059][ C1] skb_mac_gso_segment+0x97/0x110 [19185.874939][ C1] __skb_gso_segment+0xb2/0x160 [19185.883646][ C1] udp_queue_rcv_skb+0xc3/0x1d0 [19185.892319][ C1] udp_unicast_rcv_skb+0x75/0x90 [19185.900979][ C1] ip_protocol_deliver_rcu+0xd2/0x200 [19185.910003][ C1] ip_local_deliver_finish+0x44/0x60 [19185.918757][ C1] __netif_receive_skb_one_core+0x8b/0xa0 [19185.927834][ C1] process_backlog+0x88/0x130 [19185.935840][ C1] __napi_poll+0x27/0x150 [19185.943447][ C1] net_rx_action+0x27e/0x5f0 [19185.951331][ C1] ? mlx5_cq_tasklet_cb+0x70/0x160 [mlx5_core] [19185.960848][ C1] __do_softirq+0xbc/0x25d [19185.968607][ C1] irq_exit_rcu+0x83/0xb0 [19185.976247][ C1] common_interrupt+0x43/0xa0 [19185.984235][ C1] asm_common_interrupt+0x22/0x40 ... [19186.094106][ C1] </TASK>Show less

In the Linux kernel, the following vulnerability has been resolved: firewire: fix memory leak for payload of request subaction to IEC 61883-1 FCP region This patch is fix for Linux kernel v2.6.33 or later. For request subaction to IEC 61883-1 FCP region, Linux FireWire subsystem have had an issue of use-after-free. The subsystem allows multiple user space listeners to the region, while data of the payload was likely released before the listeners execute read(2) to access to it for copying to user space. The issue was fixed by a commit 281e20323ab7 ("firewire: core: fix use-after-free regression in FCP handler"). The object of payload is duplicated in kernel space for each listener. When the listener executes ioctl(2) with FW_CDEV_IOC_SEND_RESPONSE request, the object is going to be released. However, it causes memory leak since the commit relies on call of release_request() in drivers/firewire/core-cdev.c. Against the expectation, the function is never called due to the design of release_client_resource(). The function delegates release task to caller when called with non-NULL fourth argument. The implementation of ioctl_send_response() is the case. It should release the object explicitly. This commit fixes the bug.Show less

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda/via: Avoid potential array out-of-bound in add_secret_dac_path() snd_hda_get_connections() can return a negative error code. It may lead to accessing 'conn' array at a negative index. Found by Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: ipc4-mtrace: prevent underflow in sof_ipc4_priority_mask_dfs_write() The "id" comes from the user. Change the type to unsigned to prevent an array underflow.Show less

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener A listening socket linked to a sockmap has its sk_prot overridden. It points to one of the struct proto variants in tcp_bpf_prots. The variant depends on the socket's family and which sockmap programs are attached. A child socket cloned from a TCP listener initially inherits their sk_prot. But before cloning is finished, we restore the child's proto to the listener's original non-tcp_bpf_prots one. This happens in tcp_create_openreq_child -> tcp_bpf_clone. Today, in tcp_bpf_clone we detect if the child's proto should be restored by checking only for the TCP_BPF_BASE proto variant. This is not correct. The sk_prot of listening socket linked to a sockmap can point to to any variant in tcp_bpf_prots. If the listeners sk_prot happens to be not the TCP_BPF_BASE variant, then the child socket unintentionally is left if the inherited sk_prot by tcp_bpf_clone. This leads to issues like infinite recursion on close [1], because the child state is otherwise not set up for use with tcp_bpf_prot operations. Adjust the check in tcp_bpf_clone to detect all of tcp_bpf_prots variants. Note that it wouldn't be sufficient to check the socket state when overriding the sk_prot in tcp_bpf_update_proto in order to always use the TCP_BPF_BASE variant for listening sockets. Since commit b8b8315e39ff ("bpf, sockmap: Remove unhash handler for BPF sockmap usage") it is possible for a socket to transition to TCP_LISTEN state while already linked to a sockmap, e.g. connect() -> insert into map -> connect(AF_UNSPEC) -> listen(). [1]: https://lore.kernel.org/all/00000000000073b14905ef2e7401@google.com/Show less

In the Linux kernel, the following vulnerability has been resolved: arm64: dts: imx8mm-verdin: Do not power down eth-phy Currently if suspending using either freeze or memory state, the fec driver tries to power down the phy which leads to crash of the kernel and non-responsible kernel with the following call trace: [ 24.839889 ] Call trace: [ 24.839892 ] phy_error+0x18/0x60 [ 24.839898 ] kszphy_handle_interrupt+0x6c/0x80 [ 24.839903 ] phy_interrupt+0x20/0x2c [ 24.839909 ] irq_thread_fn+0x30/0xa0 [ 24.839919 ] irq_thread+0x178/0x2c0 [ 24.839925 ] kthread+0x154/0x160 [ 24.839932 ] ret_from_fork+0x10/0x20 Since there is currently no functionality in the phy subsystem to power down phys let's just disable the feature of powering-down the ethernet phy.Show less

In the Linux kernel, the following vulnerability has been resolved: net: phy: dp83822: Fix null pointer access on DP83825/DP83826 devices The probe() function is only used for the DP83822 PHY, leaving the private data pointer uninitialized for the smaller DP83825/26 models. While all uses of the private data structure are hidden in 82822 specific callbacks, configuring the interrupt is shared across all models. This causes a NULL pointer dereference on the smaller PHYs as it accesses the private data unchecked. Verifying the pointer avoids that.Show less

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for bfqq in bic_set_bfqq() After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"), bic->bfqq will be accessed in bic_set_bfqq(), however, in some context bic->bfqq will be freed, and bic_set_bfqq() is called with the freed bic->bfqq. Fix the problem by always freeing bfqq after bic_set_bfqq().Show less

In the Linux kernel, the following vulnerability has been resolved: fscache: Use wait_on_bit() to wait for the freeing of relinquished volume The freeing of relinquished volume will wake up the pending volume acquisition by using wake_up_bit(), however it is mismatched with wait_var_event() used in fscache_wait_on_volume_collision() and it will never wake up the waiter in the wait-queue because these two functions operate on different wait-queues. According to the implementation in fscache_wait_on_volume_collision(), if the wake-up of pending acquisition is delayed longer than 20 seconds (e.g., due to the delay of on-demand fd closing), the first wait_var_event_timeout() will timeout and the following wait_var_event() will hang forever as shown below: FS-Cache: Potential volume collision new=00000024 old=00000022 ...... INFO: task mount:1148 blocked for more than 122 seconds. Not tainted 6.1.0-rc6+ #1 task:mount state:D stack:0 pid:1148 ppid:1 Call Trace: <TASK> __schedule+0x2f6/0xb80 schedule+0x67/0xe0 fscache_wait_on_volume_collision.cold+0x80/0x82 __fscache_acquire_volume+0x40d/0x4e0 erofs_fscache_register_volume+0x51/0xe0 [erofs] erofs_fscache_register_fs+0x19c/0x240 [erofs] erofs_fc_fill_super+0x746/0xaf0 [erofs] vfs_get_super+0x7d/0x100 get_tree_nodev+0x16/0x20 erofs_fc_get_tree+0x20/0x30 [erofs] vfs_get_tree+0x24/0xb0 path_mount+0x2fa/0xa90 do_mount+0x7c/0xa0 __x64_sys_mount+0x8b/0xe0 do_syscall_64+0x30/0x60 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Considering that wake_up_bit() is more selective, so fix it by using wait_on_bit() instead of wait_var_event() to wait for the freeing of relinquished volume. In addition because waitqueue_active() is used in wake_up_bit() and clear_bit() doesn't imply any memory barrier, use clear_and_wake_up_bit() to add the missing memory barrier between cursor->flags and waitqueue_active().Show less

In the Linux kernel, the following vulnerability has been resolved: drm/i915: Fix request ref counting during error capture & debugfs dump When GuC support was added to error capture, the reference counting around the request object was broken. Fix it up. The context based search manages the spinlocking around the search internally. So it needs to grab the reference count internally as well. The execlist only request based search relies on external locking, so it needs an external reference count but within the spinlock not outside it. The only other caller of the context based search is the code for dumping engine state to debugfs. That code wasn't previously getting an explicit reference at all as it does everything while holding the execlist specific spinlock. So, that needs updaing as well as that spinlock doesn't help when using GuC submission. Rather than trying to conditionally get/put depending on submission model, just change it to always do the get/put. v2: Explicitly document adding an extra blank line in some dense code (Andy Shevchenko). Fix multiple potential null pointer derefs in case of no request found (some spotted by Tvrtko, but there was more!). Also fix a leaked request in case of !started and another in __guc_reset_context now that intel_context_find_active_request is actually reference counting the returned request. v3: Add a _get suffix to intel_context_find_active_request now that it grabs a reference (Daniele). v4: Split the intel_guc_find_hung_context change to a separate patch and rename intel_context_find_active_request_get to intel_context_get_active_request (Tvrtko). v5: s/locking/reference counting/ in commit message (Tvrtko) (cherry picked from commit 3700e353781e27f1bc7222f51f2cc36cbeb9b4ec)Show less