In the Linux kernel, the following vulnerability has been resolved: riscv: prevent pt_regs corruption for secondary idle threads Top of the kernel thread stack should be reserved for pt_regs. However this is not the case for the idle threads of the secondary boot harts. Their stacks overlap with their pt_regs, so both may get corrupted. Similar issue has been fixed for the primary hart, see c7cdd96eca28 ("riscv: prevent stack corruption by reserving task_pt_regs(p) early"). However that fix was not propagated to the secondary harts. The problem has been noticed in some CPU hotplug tests with V enabled. The function smp_callin stored several registers on stack, corrupting top of pt_regs structure including status field. As a result, kernel attempted to save or restore inexistent V context.

In the Linux kernel, the following vulnerability has been resolved: drm: zynqmp_dpsub: Always register bridge We must always register the DRM bridge, since zynqmp_dp_hpd_work_func calls drm_bridge_hpd_notify, which in turn expects hpd_mutex to be initialized. We do this before zynqmp_dpsub_drm_init since that calls drm_bridge_attach. This fixes the following lockdep warning: [ 19.217084] ------------[ cut here ]------------ [ 19.227530] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 19.227768] WARNING: CPU: 0 PID: 140 at kernel/locking/mutex.c:582 __mutex_lock+0x4bc/0x550 [ 19.241696] Modules linked in: [ 19.244937] CPU: 0 PID: 140 Comm: kworker/0:4 Not tainted 6.6.20+ #96 [ 19.252046] Hardware name: xlnx,zynqmp (DT) [ 19.256421] Workqueue: events zynqmp_dp_hpd_work_func [ 19.261795] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 19.269104] pc : __mutex_lock+0x4bc/0x550 [ 19.273364] lr : __mutex_lock+0x4bc/0x550 [ 19.277592] sp : ffffffc085c5bbe0 [ 19.281066] x29: ffffffc085c5bbe0 x28: 0000000000000000 x27: ffffff88009417f8 [ 19.288624] x26: ffffff8800941788 x25: ffffff8800020008 x24: ffffffc082aa3000 [ 19.296227] x23: ffffffc080d90e3c x22: 0000000000000002 x21: 0000000000000000 [ 19.303744] x20: 0000000000000000 x19: ffffff88002f5210 x18: 0000000000000000 [ 19.311295] x17: 6c707369642e3030 x16: 3030613464662072 x15: 0720072007200720 [ 19.318922] x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 0000000000000001 [ 19.326442] x11: 0001ffc085c5b940 x10: 0001ff88003f388b x9 : 0001ff88003f3888 [ 19.334003] x8 : 0001ff88003f3888 x7 : 0000000000000000 x6 : 0000000000000000 [ 19.341537] x5 : 0000000000000000 x4 : 0000000000001668 x3 : 0000000000000000 [ 19.349054] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff88003f3880 [ 19.356581] Call trace: [ 19.359160] __mutex_lock+0x4bc/0x550 [ 19.363032] mutex_lock_nested+0x24/0x30 [ 19.367187] drm_bridge_hpd_notify+0x2c/0x6c [ 19.371698] zynqmp_dp_hpd_work_func+0x44/0x54 [ 19.376364] process_one_work+0x3ac/0x988 [ 19.380660] worker_thread+0x398/0x694 [ 19.384736] kthread+0x1bc/0x1c0 [ 19.388241] ret_from_fork+0x10/0x20 [ 19.392031] irq event stamp: 183 [ 19.395450] hardirqs last enabled at (183): [<ffffffc0800b9278>] finish_task_switch.isra.0+0xa8/0x2d4 [ 19.405140] hardirqs last disabled at (182): [<ffffffc081ad3754>] __schedule+0x714/0xd04 [ 19.413612] softirqs last enabled at (114): [<ffffffc080133de8>] srcu_invoke_callbacks+0x158/0x23c [ 19.423128] softirqs last disabled at (110): [<ffffffc080133de8>] srcu_invoke_callbacks+0x158/0x23c [ 19.432614] ---[ end trace 0000000000000000 ]--- (cherry picked from commit 61ba791c4a7a09a370c45b70a81b8c7d4cf6b2ae)

In the Linux kernel, the following vulnerability has been resolved: dma-mapping: benchmark: handle NUMA_NO_NODE correctly cpumask_of_node() can be called for NUMA_NO_NODE inside do_map_benchmark() resulting in the following sanitizer report: UBSAN: array-index-out-of-bounds in ./arch/x86/include/asm/topology.h:72:28 index -1 is out of range for type 'cpumask [64][1]' CPU: 1 PID: 990 Comm: dma_map_benchma Not tainted 6.9.0-rc6 #29 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117) ubsan_epilogue (lib/ubsan.c:232) __ubsan_handle_out_of_bounds (lib/ubsan.c:429) cpumask_of_node (arch/x86/include/asm/topology.h:72) [inline] do_map_benchmark (kernel/dma/map_benchmark.c:104) map_benchmark_ioctl (kernel/dma/map_benchmark.c:246) full_proxy_unlocked_ioctl (fs/debugfs/file.c:333) __x64_sys_ioctl (fs/ioctl.c:890) do_syscall_64 (arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Use cpumask_of_node() in place when binding a kernel thread to a cpuset of a particular node. Note that the provided node id is checked inside map_benchmark_ioctl(). It's just a NUMA_NO_NODE case which is not handled properly later. Found by Linux Verification Center (linuxtesting.org).

In the Linux kernel, the following vulnerability has been resolved: dma-buf/sw-sync: don't enable IRQ from sync_print_obj() Since commit a6aa8fca4d79 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context") by error replaced spin_unlock_irqrestore() with spin_unlock_irq() for both sync_debugfs_show() and sync_print_obj() despite sync_print_obj() is called from sync_debugfs_show(), lockdep complains inconsistent lock state warning. Use plain spin_{lock,unlock}() for sync_print_obj(), for sync_debugfs_show() is already using spin_{lock,unlock}_irq().

In the Linux kernel, the following vulnerability has been resolved: tracing/probes: fix error check in parse_btf_field() btf_find_struct_member() might return NULL or an error via the ERR_PTR() macro. However, its caller in parse_btf_field() only checks for the NULL condition. Fix this by using IS_ERR() and returning the error up the stack.

In the Linux kernel, the following vulnerability has been resolved: tpm_tis_spi: Account for SPI header when allocating TPM SPI xfer buffer The TPM SPI transfer mechanism uses MAX_SPI_FRAMESIZE for computing the maximum transfer length and the size of the transfer buffer. As such, it does not account for the 4 bytes of header that prepends the SPI data frame. This can result in out-of-bounds accesses and was confirmed with KASAN. Introduce SPI_HDRSIZE to account for the header and use to allocate the transfer buffer.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix loop termination condition in gss_free_in_token_pages() The in_token->pages[] array is not NULL terminated. This results in the following KASAN splat: KASAN: maybe wild-memory-access in range [0x04a2013400000008-0x04a201340000000f]

In the Linux kernel, the following vulnerability has been resolved: ovl: fix NULL pointer dereference in copy up warning This patch is fixing a NULL pointer dereference to get a recently introduced warning message working.

In the Linux kernel, the following vulnerability has been resolved: selinux: fix double free of cond_list on error paths On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop. Also consistently reset the cond_list pointer to NULL after freeing. [PM: fix line lengths in the description]

In the Linux kernel, the following vulnerability has been resolved: ALSA: hda: Fix UAF of leds class devs at unbinding The LED class devices that are created by HD-audio codec drivers are registered via devm_led_classdev_register() and associated with the HD-audio codec device. Unfortunately, it turned out that the devres release doesn't work for this case; namely, since the codec resource release happens before the devm call chain, it triggers a NULL dereference or a UAF for a stale set_brightness_delay callback. For fixing the bug, this patch changes the LED class device register and unregister in a manual manner without devres, keeping the instances in hda_gen_spec.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock between quota disable and qgroup rescan worker Quota disable ioctl starts a transaction before waiting for the qgroup rescan worker completes. However, this wait can be infinite and results in deadlock because of circular dependency among the quota disable ioctl, the qgroup rescan worker and the other task with transaction such as block group relocation task. The deadlock happens with the steps following: 1) Task A calls ioctl to disable quota. It starts a transaction and waits for qgroup rescan worker completes. 2) Task B such as block group relocation task starts a transaction and joins to the transaction that task A started. Then task B commits to the transaction. In this commit, task B waits for a commit by task A. 3) Task C as the qgroup rescan worker starts its job and starts a transaction. In this transaction start, task C waits for completion of the transaction that task A started and task B committed. This deadlock was found with fstests test case btrfs/115 and a zoned null_blk device. The test case enables and disables quota, and the block group reclaim was triggered during the quota disable by chance. The deadlock was also observed by running quota enable and disable in parallel with 'btrfs balance' command on regular null_blk devices. An example report of the deadlock: [372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds. [372.479944] Not tainted 5.16.0-rc8 #7 [372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [372.493898] task:kworker/u16:6 state:D stack: 0 pid: 103 ppid: 2 flags:0x00004000 [372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs] [372.510782] Call Trace: [372.514092] <TASK> [372.521684] __schedule+0xb56/0x4850 [372.530104] ? io_schedule_timeout+0x190/0x190 [372.538842] ? lockdep_hardirqs_on+0x7e/0x100 [372.547092] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.555591] schedule+0xe0/0x270 [372.561894] btrfs_commit_transaction+0x18bb/0x2610 [btrfs] [372.570506] ? btrfs_apply_pending_changes+0x50/0x50 [btrfs] [372.578875] ? free_unref_page+0x3f2/0x650 [372.585484] ? finish_wait+0x270/0x270 [372.591594] ? release_extent_buffer+0x224/0x420 [btrfs] [372.599264] btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs] [372.607157] ? lock_release+0x3a9/0x6d0 [372.613054] ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs] [372.620960] ? do_raw_spin_lock+0x11e/0x250 [372.627137] ? rwlock_bug.part.0+0x90/0x90 [372.633215] ? lock_is_held_type+0xe4/0x140 [372.639404] btrfs_work_helper+0x1ae/0xa90 [btrfs] [372.646268] process_one_work+0x7e9/0x1320 [372.652321] ? lock_release+0x6d0/0x6d0 [372.658081] ? pwq_dec_nr_in_flight+0x230/0x230 [372.664513] ? rwlock_bug.part.0+0x90/0x90 [372.670529] worker_thread+0x59e/0xf90 [372.676172] ? process_one_work+0x1320/0x1320 [372.682440] kthread+0x3b9/0x490 [372.687550] ? _raw_spin_unlock_irq+0x24/0x50 [372.693811] ? set_kthread_struct+0x100/0x100 [372.700052] ret_from_fork+0x22/0x30 [372.705517] </TASK> [372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds. [372.729827] Not tainted 5.16.0-rc8 #7 [372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [372.767106] task:btrfs-transacti state:D stack: 0 pid: 2347 ppid: 2 flags:0x00004000 [372.787776] Call Trace: [372.801652] <TASK> [372.812961] __schedule+0xb56/0x4850 [372.830011] ? io_schedule_timeout+0x190/0x190 [372.852547] ? lockdep_hardirqs_on+0x7e/0x100 [372.871761] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [372.886792] schedule+0xe0/0x270 [372.901685] wait_current_trans+0x22c/0x310 [btrfs] [372.919743] ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs] [372.938923] ? finish_wait+0x270/0x270 [372.959085] ? join_transaction+0xc7 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free after failure to create a snapshot At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and then attach it to the transaction's list of pending snapshots. After that we call btrfs_commit_transaction(), and if that returns an error we jump to 'fail' label, where we kfree() the pending snapshot structure. This can result in a later use-after-free of the pending snapshot: 1) We allocated the pending snapshot and added it to the transaction's list of pending snapshots; 2) We call btrfs_commit_transaction(), and it fails either at the first call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups(). In both cases, we don't abort the transaction and we release our transaction handle. We jump to the 'fail' label and free the pending snapshot structure. We return with the pending snapshot still in the transaction's list; 3) Another task commits the transaction. This time there's no error at all, and then during the transaction commit it accesses a pointer to the pending snapshot structure that the snapshot creation task has already freed, resulting in a user-after-free. This issue could actually be detected by smatch, which produced the following warning: fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list So fix this by not having the snapshot creation ioctl directly add the pending snapshot to the transaction's list. Instead add the pending snapshot to the transaction handle, and then at btrfs_commit_transaction() we add the snapshot to the list only when we can guarantee that any error returned after that point will result in a transaction abort, in which case the ioctl code can safely free the pending snapshot and no one can access it anymore.

In the Linux kernel, the following vulnerability has been resolved: isdn: cpai: check ctr->cnr to avoid array index out of bound The cmtp_add_connection() would add a cmtp session to a controller and run a kernel thread to process cmtp. __module_get(THIS_MODULE); session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d", session->num); During this process, the kernel thread would call detach_capi_ctr() to detach a register controller. if the controller was not attached yet, detach_capi_ctr() would trigger an array-index-out-bounds bug. [ 46.866069][ T6479] UBSAN: array-index-out-of-bounds in drivers/isdn/capi/kcapi.c:483:21 [ 46.867196][ T6479] index -1 is out of range for type 'capi_ctr *[32]' [ 46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpd_ctr_0 Not tainted 5.15.0-rc2+ #8 [ 46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 46.870107][ T6479] Call Trace: [ 46.870473][ T6479] dump_stack_lvl+0x57/0x7d [ 46.870974][ T6479] ubsan_epilogue+0x5/0x40 [ 46.871458][ T6479] __ubsan_handle_out_of_bounds.cold+0x43/0x48 [ 46.872135][ T6479] detach_capi_ctr+0x64/0xc0 [ 46.872639][ T6479] cmtp_session+0x5c8/0x5d0 [ 46.873131][ T6479] ? __init_waitqueue_head+0x60/0x60 [ 46.873712][ T6479] ? cmtp_add_msgpart+0x120/0x120 [ 46.874256][ T6479] kthread+0x147/0x170 [ 46.874709][ T6479] ? set_kthread_struct+0x40/0x40 [ 46.875248][ T6479] ret_from_fork+0x1f/0x30 [ 46.875773][ T6479]

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: refactor malicious adv data check Check for out-of-bound read was being performed at the end of while num_reports loop, and would fill journal with false positives. Added check to beginning of loop processing so that it doesn't get checked after ptr has been advanced.

In the Linux kernel, the following vulnerability has been resolved: nfc: fix segfault in nfc_genl_dump_devices_done When kmalloc in nfc_genl_dump_devices() fails then nfc_genl_dump_devices_done() segfaults as below KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 25 Comm: kworker/0:1 Not tainted 5.16.0-rc4-01180-g2a987e65025e-dirty #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-6.fc35 04/01/2014 Workqueue: events netlink_sock_destruct_work RIP: 0010:klist_iter_exit+0x26/0x80 Call Trace: <TASK> class_dev_iter_exit+0x15/0x20 nfc_genl_dump_devices_done+0x3b/0x50 genl_lock_done+0x84/0xd0 netlink_sock_destruct+0x8f/0x270 __sk_destruct+0x64/0x3b0 sk_destruct+0xa8/0xd0 __sk_free+0x2e8/0x3d0 sk_free+0x51/0x90 netlink_sock_destruct_work+0x1c/0x20 process_one_work+0x411/0x710 worker_thread+0x6fd/0xa80

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix null ptr access msm_ioctl_gem_submit() Fix the below null pointer dereference in msm_ioctl_gem_submit(): 26545.260705: Call trace: 26545.263223: kref_put+0x1c/0x60 26545.266452: msm_ioctl_gem_submit+0x254/0x744 26545.270937: drm_ioctl_kernel+0xa8/0x124 26545.274976: drm_ioctl+0x21c/0x33c 26545.278478: drm_compat_ioctl+0xdc/0xf0 26545.282428: __arm64_compat_sys_ioctl+0xc8/0x100 26545.287169: el0_svc_common+0xf8/0x250 26545.291025: do_el0_svc_compat+0x28/0x54 26545.295066: el0_svc_compat+0x10/0x1c 26545.298838: el0_sync_compat_handler+0xa8/0xcc 26545.303403: el0_sync_compat+0x188/0x1c0 26545.307445: Code: d503201f d503201f 52800028 4b0803e8 (b8680008) 26545.318799: Kernel panic - not syncing: Oops: Fatal exception

In the Linux kernel, the following vulnerability has been resolved: net: netlink: af_netlink: Prevent empty skb by adding a check on len. Adding a check on len parameter to avoid empty skb. This prevents a division error in netem_enqueue function which is caused when skb->len=0 and skb->data_len=0 in the randomized corruption step as shown below. skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); Crash Report: [ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 [ 343.216110] netem: version 1.3 [ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+ [ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] [ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f 74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 [ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: 0000000000000000 [ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: ffffffff94fb8445 [ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: 0000000000000000 [ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: 0000000000000020 [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: 00000000000006e0 [ 343.250076] Call Trace: [ 343.250423] <TASK> [ 343.250713] ? memcpy+0x4d/0x60 [ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] [ 343.253102] ? stack_trace_save+0x87/0xb0 [ 343.253655] ? filter_irq_stacks+0xb0/0xb0 [ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.254837] ? __kasan_check_write+0x14/0x20 [ 343.255418] ? _raw_spin_lock+0x88/0xd6 [ 343.255953] dev_qdisc_enqueue+0x50/0x180 [ 343.256508] __dev_queue_xmit+0x1a7e/0x3090 [ 343.257083] ? netdev_core_pick_tx+0x300/0x300 [ 343.257690] ? check_kcov_mode+0x10/0x40 [ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 343.258899] ? __kasan_init_slab_obj+0x24/0x30 [ 343.259529] ? setup_object.isra.71+0x23/0x90 [ 343.260121] ? new_slab+0x26e/0x4b0 [ 343.260609] ? kasan_poison+0x3a/0x50 [ 343.261118] ? kasan_unpoison+0x28/0x50 [ 343.261637] ? __kasan_slab_alloc+0x71/0x90 [ 343.262214] ? memcpy+0x4d/0x60 [ 343.262674] ? write_comp_data+0x2f/0x90 [ 343.263209] ? __kasan_check_write+0x14/0x20 [ 343.263802] ? __skb_clone+0x5d6/0x840 [ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.264958] dev_queue_xmit+0x1c/0x20 [ 343.265470] netlink_deliver_tap+0x652/0x9c0 [ 343.266067] netlink_unicast+0x5a0/0x7f0 [ 343.266608] ? netlink_attachskb+0x860/0x860 [ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.267820] ? write_comp_data+0x2f/0x90 [ 343.268367] netlink_sendmsg+0x922/0xe80 [ 343.268899] ? netlink_unicast+0x7f0/0x7f0 [ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.270099] ? write_comp_data+0x2f/0x90 [ 343.270644] ? netlink_unicast+0x7f0/0x7f0 [ 343.271210] sock_sendmsg+0x155/0x190 [ 343.271721] ____sys_sendmsg+0x75f/0x8f0 [ 343.272262] ? kernel_sendmsg+0x60/0x60 [ 343.272788] ? write_comp_data+0x2f/0x90 [ 343.273332] ? write_comp_data+0x2f/0x90 [ 343.273869] ___sys_sendmsg+0x10f/0x190 [ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80 [ 343.274984] ? slab_post_alloc_hook+0x70/0x230 [ 343.275597] ? futex_wait_setup+0x240/0x240 [ 343.276175] ? security_file_alloc+0x3e/0x170 [ 343.276779] ? write_comp_d ---truncated---

In the Linux kernel, the following vulnerability has been resolved: dm btree remove: fix use after free in rebalance_children() Move dm_tm_unlock() after dm_tm_dec().

In the Linux kernel, the following vulnerability has been resolved: btrfs: use latest_dev in btrfs_show_devname The test case btrfs/238 reports the warning below: WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs] CPU: 2 PID: 1 Comm: systemd Tainted: G W O 5.14.0-rc1-custom #72 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: btrfs_show_devname+0x108/0x1b4 [btrfs] show_mountinfo+0x234/0x2c4 m_show+0x28/0x34 seq_read_iter+0x12c/0x3c4 vfs_read+0x29c/0x2c8 ksys_read+0x80/0xec __arm64_sys_read+0x28/0x34 invoke_syscall+0x50/0xf8 do_el0_svc+0x88/0x138 el0_svc+0x2c/0x8c el0t_64_sync_handler+0x84/0xe4 el0t_64_sync+0x198/0x19c Reason: While btrfs_prepare_sprout() moves the fs_devices::devices into fs_devices::seed_list, the btrfs_show_devname() searches for the devices and found none, leading to the warning as in above. Fix: latest_dev is updated according to the changes to the device list. That means we could use the latest_dev->name to show the device name in /proc/self/mounts, the pointer will be always valid as it's assigned before the device is deleted from the list in remove or replace. The RCU protection is sufficient as the device structure is freed after synchronization.

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Don't call kcalloc() if size arg is zero If the size arg to kcalloc() is zero, it returns ZERO_SIZE_PTR. Because of that, for a following NULL pointer check to work on the returned pointer, kcalloc() must not be called with the size arg equal to zero. Return early without error before the kcalloc() call if size arg is zero. BUG: KASAN: null-ptr-deref in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: null-ptr-deref in sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 Write of size 4 at addr 0000000000000010 by task syz-executor.1/22789 CPU: 1 PID: 22789 Comm: syz-executor.1 Not tainted 5.15.0-syzk #1 Hardware name: Red Hat KVM, BIOS 1.13.0-2 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [inline] kasan_report.cold.14+0x112/0x117 mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189 memcpy+0x3b/0x60 mm/kasan/shadow.c:66 memcpy include/linux/fortify-string.h:191 [inline] sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 do_dout_fetch drivers/scsi/scsi_debug.c:2954 [inline] do_dout_fetch drivers/scsi/scsi_debug.c:2946 [inline] resp_verify+0x49e/0x930 drivers/scsi/scsi_debug.c:4276 schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5478 scsi_debug_queuecommand+0x8c9/0x1ec0 drivers/scsi/scsi_debug.c:7533 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1520 [inline] scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699 blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639 __blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325 blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358 __blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761 __blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838 blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891 blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474 blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62 blk_execute_rq+0xdb/0x360 block/blk-exec.c:102 sg_scsi_ioctl drivers/scsi/scsi_ioctl.c:621 [inline] scsi_ioctl+0x8bb/0x15c0 drivers/scsi/scsi_ioctl.c:930 sg_ioctl_common+0x172d/0x2710 drivers/scsi/sg.c:1112 sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1165 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae