In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null checks for 'stream' and 'plane' before dereferencing This commit adds null checks for the 'stream' and 'plane' variables in the dcn30_apply_idle_power_optimizations function. These variables were previously assumed to be null at line 922, but they were used later in the code without checking if they were null. This could potentially lead to a null pointer dereference, which would cause a crash. The null checks ensure that 'stream' and 'plane' are not null before they are used, preventing potential crashes. Fixes the below static smatch checker: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:938 dcn30_apply_idle_power_optimizations() error: we previously assumed 'stream' could be null (see line 922) drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:940 dcn30_apply_idle_power_optimizations() error: we previously assumed 'plane' could be null (see line 922)

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

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix tc flower deletion for VLAN priority Rx steering To replicate the issue:- 1) Add 1 flower filter for VLAN Priority based frame steering:- $ IFDEVNAME=eth0 $ tc qdisc add dev $IFDEVNAME ingress $ tc qdisc add dev $IFDEVNAME root mqprio num_tc 8 \ map 0 1 2 3 4 5 6 7 0 0 0 0 0 0 0 0 \ queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0 $ tc filter add dev $IFDEVNAME parent ffff: protocol 802.1Q \ flower vlan_prio 0 hw_tc 0 2) Get the 'pref' id $ tc filter show dev $IFDEVNAME ingress 3) Delete a specific tc flower record (say pref 49151) $ tc filter del dev $IFDEVNAME parent ffff: pref 49151 From dmesg, we will observe kernel NULL pointer ooops [ 197.170464] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 197.171367] #PF: supervisor read access in kernel mode [ 197.171367] #PF: error_code(0x0000) - not-present page [ 197.171367] PGD 0 P4D 0 [ 197.171367] Oops: 0000 [#1] PREEMPT SMP NOPTI <snip> [ 197.171367] RIP: 0010:tc_setup_cls+0x20b/0x4a0 [stmmac] <snip> [ 197.171367] Call Trace: [ 197.171367] <TASK> [ 197.171367] ? __stmmac_disable_all_queues+0xa8/0xe0 [stmmac] [ 197.171367] stmmac_setup_tc_block_cb+0x70/0x110 [stmmac] [ 197.171367] tc_setup_cb_destroy+0xb3/0x180 [ 197.171367] fl_hw_destroy_filter+0x94/0xc0 [cls_flower] The above issue is due to previous incorrect implementation of tc_del_vlan_flow(), shown below, that uses flow_cls_offload_flow_rule() to get struct flow_rule *rule which is no longer valid for tc filter delete operation. struct flow_rule *rule = flow_cls_offload_flow_rule(cls); struct flow_dissector *dissector = rule->match.dissector; So, to ensure tc_del_vlan_flow() deletes the right VLAN cls record for earlier configured RX queue (configured by hw_tc) in tc_add_vlan_flow(), this patch introduces stmmac_rfs_entry as driver-side flow_cls_offload record for 'RX frame steering' tc flower, currently used for VLAN priority. The implementation has taken consideration for future extension to include other type RX frame steering such as EtherType based. v2: - Clean up overly extensive backtrace and rewrite git message to better explain the kernel NULL pointer issue.

In the Linux kernel, the following vulnerability has been resolved: platform/x86: ideapad-laptop: fix a NULL pointer dereference The third parameter of dytc_cql_command should not be NULL since it will be dereferenced immediately.

In the Linux kernel, the following vulnerability has been resolved: drm/admgpu: fix dereferencing null pointer context When user space sets an invalid ta type, the pointer context will be empty. So it need to check the pointer context before using it

In the Linux kernel, the following vulnerability has been resolved: memcg_write_event_control(): fix a user-triggerable oops we are *not* guaranteed that anything past the terminating NUL is mapped (let alone initialized with anything sane).

In the Linux kernel, the following vulnerability has been resolved: iwlwifi: mvm: Fix possible NULL dereference In __iwl_mvm_remove_time_event() check that 'te_data->vif' is NULL before dereferencing it.

In the Linux kernel, the following vulnerability has been resolved: drm/meson: fix shutdown crash when component not probed When main component is not probed, by example when the dw-hdmi module is not loaded yet or in probe defer, the following crash appears on shutdown: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038 ... pc : meson_drv_shutdown+0x24/0x50 lr : platform_drv_shutdown+0x20/0x30 ... Call trace: meson_drv_shutdown+0x24/0x50 platform_drv_shutdown+0x20/0x30 device_shutdown+0x158/0x360 kernel_restart_prepare+0x38/0x48 kernel_restart+0x18/0x68 __do_sys_reboot+0x224/0x250 __arm64_sys_reboot+0x24/0x30 ... Simply check if the priv struct has been allocated before using it.

In the Linux kernel, the following vulnerability has been resolved: mptcp: never allow the PM to close a listener subflow Currently, when deleting an endpoint the netlink PM treverses all the local MPTCP sockets, regardless of their status. If an MPTCP listener socket is bound to the IP matching the delete endpoint, the listener TCP socket will be closed. That is unexpected, the PM should only affect data subflows. Additionally, syzbot was able to trigger a NULL ptr dereference due to the above: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897 Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016 RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000 R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0 Call Trace: <TASK> lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 finish_wait+0xc0/0x270 kernel/sched/wait.c:400 inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline] inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497 mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865 inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739 mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345 do_accept+0x382/0x510 net/socket.c:1773 __sys_accept4_file+0x7e/0xe0 net/socket.c:1816 __sys_accept4+0xb0/0x100 net/socket.c:1846 __do_sys_accept net/socket.c:1864 [inline] __se_sys_accept net/socket.c:1861 [inline] __x64_sys_accept+0x71/0xb0 net/socket.c:1861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f177cd8b8e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000 </TASK> Fix the issue explicitly skipping MPTCP socket in TCP_LISTEN status.

In the Linux kernel, the following vulnerability has been resolved: tee: amdtee: fix an IS_ERR() vs NULL bug The __get_free_pages() function does not return error pointers it returns NULL so fix this condition to avoid a NULL dereference.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix null pointer dereference in svc_rqst_free() When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). Fix it by adding a null check. Addresses-Coverity: ("Dereference after null check")

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Fix NULL pointer dereference for ->get_features() get_features ops of pci_epc_ops may return NULL, causing NULL pointer dereference in pci_epf_test_alloc_space function. Let us add a check for pci_epc_feature pointer in pci_epf_test_bind before we access it to avoid any such NULL pointer dereference and return -ENOTSUPP in case pci_epc_feature is not found. When the patch is not applied and EPC features is not implemented in the platform driver, we see the following dump due to kernel NULL pointer dereference. Call trace: pci_epf_test_bind+0xf4/0x388 pci_epf_bind+0x3c/0x80 pci_epc_epf_link+0xa8/0xcc configfs_symlink+0x1a4/0x48c vfs_symlink+0x104/0x184 do_symlinkat+0x80/0xd4 __arm64_sys_symlinkat+0x1c/0x24 el0_svc_common.constprop.3+0xb8/0x170 el0_svc_handler+0x70/0x88 el0_svc+0x8/0x640 Code: d2800581 b9403ab9 f9404ebb 8b394f60 (f9400400) ---[ end trace a438e3c5a24f9df0 ]---

In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: check return value after calling platform_get_resource() It will cause null-ptr-deref if platform_get_resource() returns NULL, we need check the return value.

In the Linux kernel, the following vulnerability has been resolved: usb: misc: brcmstb-usb-pinmap: check return value after calling platform_get_resource() It will cause null-ptr-deref if platform_get_resource() returns NULL, we need check the return value.

In the Linux kernel, the following vulnerability has been resolved: ACPI: fix NULL pointer dereference Commit 71f642833284 ("ACPI: utils: Fix reference counting in for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer that was possibly NULL. That fails miserably, because that helper inline function is not set up to handle that case. Just make acpi_dev_put() silently accept a NULL pointer, rather than calling down to put_device() with an invalid offset off that NULL pointer.

In the Linux kernel, the following vulnerability has been resolved: bonding: fix null pointer deref in bond_ipsec_offload_ok We must check if there is an active slave before dereferencing the pointer.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/pm: Fix the null pointer dereference for smu7 optimize the code to avoid pass a null pointer (hwmgr->backend) to function smu7_update_edc_leakage_table.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix the null pointer dereference to ras_manager Check ras_manager before using it

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null checker before passing variables Checks null pointer before passing variables to functions. This fixes 3 NULL_RETURNS issues reported by Coverity.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/pm: Fix the null pointer dereference in apply_state_adjust_rules Check the pointer value to fix potential null pointer dereference

In the Linux kernel, the following vulnerability has been resolved: ASoC: cs-amp-lib: Fix NULL pointer crash if efi.get_variable is NULL Call efi_rt_services_supported() to check that efi.get_variable exists before calling it.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Fix the null pointer dereference for vega10_hwmgr Check return value and conduct null pointer handling to avoid null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: mmc: mmc_test: Fix NULL dereference on allocation failure If the "test->highmem = alloc_pages()" allocation fails then calling __free_pages(test->highmem) will result in a NULL dereference. Also change the error code to -ENOMEM instead of returning success.

In the Linux kernel, the following vulnerability has been resolved: smb/client: avoid possible NULL dereference in cifs_free_subrequest() Clang static checker (scan-build) warning: cifsglob.h:line 890, column 3 Access to field 'ops' results in a dereference of a null pointer. Commit 519be989717c ("cifs: Add a tracepoint to track credits involved in R/W requests") adds a check for 'rdata->server', and let clang throw this warning about NULL dereference. When 'rdata->credits.value != 0 && rdata->server == NULL' happens, add_credits_and_wake_if() will call rdata->server->ops->add_credits(). This will cause NULL dereference problem. Add a check for 'rdata->server' to avoid NULL dereference.

In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_rproc: Skip over memory region when node value is NULL In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts number of phandles. But phandles may be empty. So of_parse_phandle() in the parsing loop (0 < a < nph) may return NULL which is later dereferenced. Adjust this issue by adding NULL-return check. Found by Linux Verification Center (linuxtesting.org) with SVACE. [Fixed title to fit within the prescribed 70-75 charcters]

In the Linux kernel, the following vulnerability has been resolved: PCI: keystone: Fix NULL pointer dereference in case of DT error in ks_pcie_setup_rc_app_regs() If IORESOURCE_MEM is not provided in Device Tree due to any error, resource_list_first_type() will return NULL and pci_parse_request_of_pci_ranges() will just emit a warning. This will cause a NULL pointer dereference. Fix this bug by adding NULL return check. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix a possible null pointer dereference In function lpfc_xcvr_data_show, the memory allocation with kmalloc might fail, thereby making rdp_context a null pointer. In the following context and functions that use this pointer, there are dereferencing operations, leading to null pointer dereference. To fix this issue, a null pointer check should be added. If it is null, use scnprintf to notify the user and return len.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix null check for pipe_ctx->plane_state in hwss_setup_dpp This commit addresses a null pointer dereference issue in hwss_setup_dpp(). The issue could occur when pipe_ctx->plane_state is null. The fix adds a check to ensure `pipe_ctx->plane_state` is not null before accessing. This prevents a null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to truncate preallocated blocks in f2fs_file_open() chenyuwen reports a f2fs bug as below: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000011 fscrypt_set_bio_crypt_ctx+0x78/0x1e8 f2fs_grab_read_bio+0x78/0x208 f2fs_submit_page_read+0x44/0x154 f2fs_get_read_data_page+0x288/0x5f4 f2fs_get_lock_data_page+0x60/0x190 truncate_partial_data_page+0x108/0x4fc f2fs_do_truncate_blocks+0x344/0x5f0 f2fs_truncate_blocks+0x6c/0x134 f2fs_truncate+0xd8/0x200 f2fs_iget+0x20c/0x5ac do_garbage_collect+0x5d0/0xf6c f2fs_gc+0x22c/0x6a4 f2fs_disable_checkpoint+0xc8/0x310 f2fs_fill_super+0x14bc/0x1764 mount_bdev+0x1b4/0x21c f2fs_mount+0x20/0x30 legacy_get_tree+0x50/0xbc vfs_get_tree+0x5c/0x1b0 do_new_mount+0x298/0x4cc path_mount+0x33c/0x5fc __arm64_sys_mount+0xcc/0x15c invoke_syscall+0x60/0x150 el0_svc_common+0xb8/0xf8 do_el0_svc+0x28/0xa0 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec It is because inode.i_crypt_info is not initialized during below path: - mount - f2fs_fill_super - f2fs_disable_checkpoint - f2fs_gc - f2fs_iget - f2fs_truncate So, let's relocate truncation of preallocated blocks to f2fs_file_open(), after fscrypt_file_open().

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_init() Instead of getting the epc_features from pci_epc_get_features() API, use the cached pci_epf_test::epc_features value to avoid the NULL check. Since the NULL check is already performed in pci_epf_test_bind(), having one more check in pci_epf_test_core_init() is redundant and it is not possible to hit the NULL pointer dereference. Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag"), 'epc_features' got dereferenced without the NULL check, leading to the following false positive Smatch warning: drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init() error: we previously assumed 'epc_features' could be null (see line 747) Thus, remove the redundant NULL check and also use the epc_features:: {msix_capable/msi_capable} flags directly to avoid local variables. [kwilczynski: commit log]

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix null reference error when checking end of zone This patch fixes a potentially null pointer being accessed by is_end_zone_blkaddr() that checks the last block of a zone when f2fs is mounted as a single device.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Add error handling to pair_device() hci_conn_params_add() never checks for a NULL value and could lead to a NULL pointer dereference causing a crash. Fixed by adding error handling in the function.

The mac80211 subsystem in the Linux kernel before 5.12.13, when a device supporting only 5 GHz is used, allows attackers to cause a denial of service (NULL pointer dereference in the radiotap parser) by injecting a frame with 802.11a rates.

In the Linux kernel, the following vulnerability has been resolved: md: fix deadlock between mddev_suspend and flush bio Deadlock occurs when mddev is being suspended while some flush bio is in progress. It is a complex issue. T1. the first flush is at the ending stage, it clears 'mddev->flush_bio' and tries to submit data, but is blocked because mddev is suspended by T4. T2. the second flush sets 'mddev->flush_bio', and attempts to queue md_submit_flush_data(), which is already running (T1) and won't execute again if on the same CPU as T1. T3. the third flush inc active_io and tries to flush, but is blocked because 'mddev->flush_bio' is not NULL (set by T2). T4. mddev_suspend() is called and waits for active_io dec to 0 which is inc by T3. T1 T2 T3 T4 (flush 1) (flush 2) (third 3) (suspend) md_submit_flush_data mddev->flush_bio = NULL; . . md_flush_request . mddev->flush_bio = bio . queue submit_flushes . . . . md_handle_request . . active_io + 1 . . md_flush_request . . wait !mddev->flush_bio . . . . mddev_suspend . . wait !active_io . . . submit_flushes . queue_work md_submit_flush_data . //md_submit_flush_data is already running (T1) . md_handle_request wait resume The root issue is non-atomic inc/dec of active_io during flush process. active_io is dec before md_submit_flush_data is queued, and inc soon after md_submit_flush_data() run. md_flush_request active_io + 1 submit_flushes active_io - 1 md_submit_flush_data md_handle_request active_io + 1 make_request active_io - 1 If active_io is dec after md_handle_request() instead of within submit_flushes(), make_request() can be called directly intead of md_handle_request() in md_submit_flush_data(), and active_io will only inc and dec once in the whole flush process. Deadlock will be fixed. Additionally, the only difference between fixing the issue and before is that there is no return error handling of make_request(). But after previous patch cleaned md_write_start(), make_requst() only return error in raid5_make_request() by dm-raid, see commit 41425f96d7aa ("dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape)". Since dm always splits data and flush operation into two separate io, io size of flush submitted by dm always is 0, make_request() will not be called in md_submit_flush_data(). To prevent future modifications from introducing issues, add WARN_ON to ensure make_request() no error is returned in this context.

In the Linux kernel, the following vulnerability has been resolved: net: ethtool: pse-pd: Fix possible null-deref Fix a possible null dereference when a PSE supports both c33 and PoDL, but only one of the netlink attributes is specified. The c33 or PoDL PSE capabilities are already validated in the ethnl_set_pse_validate() call.

In the Linux kernel, the following vulnerability has been resolved: ASoc: PCM6240: Return directly after a failed devm_kzalloc() in pcmdevice_i2c_probe() The value “-ENOMEM” was assigned to the local variable “ret” in one if branch after a devm_kzalloc() call failed at the beginning. This error code will trigger then a pcmdevice_remove() call with a passed null pointer so that an undesirable dereference will be performed. Thus return the appropriate error code directly.

In the Linux kernel, the following vulnerability has been resolved: media: v4l: async: Fix NULL pointer dereference in adding ancillary links In v4l2_async_create_ancillary_links(), ancillary links are created for lens and flash sub-devices. These are sub-device to sub-device links and if the async notifier is related to a V4L2 device, the source sub-device of the ancillary link is NULL, leading to a NULL pointer dereference. Check the notifier's sd field is non-NULL in v4l2_async_create_ancillary_links(). [Sakari Ailus: Reword the subject and commit messages slightly.]

In the Linux kernel, the following vulnerability has been resolved: bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations") leads a NULL pointer deference in cache_set_flush(). 1721 if (!IS_ERR_OR_NULL(c->root)) 1722 list_add(&c->root->list, &c->btree_cache); >From the above code in cache_set_flush(), if previous registration code fails before allocating c->root, it is possible c->root is NULL as what it is initialized. __bch_btree_node_alloc() never returns NULL but c->root is possible to be NULL at above line 1721. This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.

In the Linux kernel, the following vulnerability has been resolved: ASoC: fsl-asoc-card: set priv->pdev before using it priv->pdev pointer was set after being used in fsl_asoc_card_audmux_init(). Move this assignment at the start of the probe function, so sub-functions can correctly use pdev through priv. fsl_asoc_card_audmux_init() dereferences priv->pdev to get access to the dev struct, used with dev_err macros. As priv is zero-initialised, there would be a NULL pointer dereference. Note that if priv->dev is dereferenced before assignment but never used, for example if there is no error to be printed, the driver won't crash probably due to compiler optimisations.

In the Linux kernel, the following vulnerability has been resolved: ASoC: fsl: fsl_qmc_audio: Check devm_kasprintf() returned value devm_kasprintf() can return a NULL pointer on failure but this returned value is not checked. Fix this lack and check the returned value.

In the Linux kernel, the following vulnerability has been resolved: virtio-pci: Check if is_avq is NULL [bug] In the virtio_pci_common.c function vp_del_vqs, vp_dev->is_avq is involved to determine whether it is admin virtqueue, but this function vp_dev->is_avq may be empty. For installations, virtio_pci_legacy does not assign a value to vp_dev->is_avq. [fix] Check whether it is vp_dev->is_avq before use. [test] Test with virsh Attach device Before this patch, the following command would crash the guest system After applying the patch, everything seems to be working fine.

In the Linux kernel, the following vulnerability has been resolved: drm/gma500: fix null pointer dereference in cdv_intel_lvds_get_modes In cdv_intel_lvds_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

arch/powerpc/perf/core-book3s.c in the Linux kernel before 5.12.13, on systems with perf_event_paranoid=-1 and no specific PMU driver support registered, allows local users to cause a denial of service (perf_instruction_pointer NULL pointer dereference and OOPS) via a "perf record" command.

In the Linux kernel, the following vulnerability has been resolved: drm/gma500: fix null pointer dereference in psb_intel_lvds_get_modes In psb_intel_lvds_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a possible NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

In the Linux kernel, the following vulnerability has been resolved: cifs: fix potential null pointer use in destroy_workqueue in init_cifs error path Dan Carpenter reported a Smack static checker warning: fs/smb/client/cifsfs.c:1981 init_cifs() error: we previously assumed 'serverclose_wq' could be null (see line 1895) The patch which introduced the serverclose workqueue used the wrong oredering in error paths in init_cifs() for freeing it on errors.

In the Linux kernel, the following vulnerability has been resolved: iommu: sprd: Avoid NULL deref in sprd_iommu_hw_en In sprd_iommu_cleanup() before calling function sprd_iommu_hw_en() dom->sdev is equal to NULL, which leads to null dereference. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: net: mediatek: Fix potential NULL pointer dereference in dummy net_device handling Move the freeing of the dummy net_device from mtk_free_dev() to mtk_remove(). Previously, if alloc_netdev_dummy() failed in mtk_probe(), eth->dummy_dev would be NULL. The error path would then call mtk_free_dev(), which in turn called free_netdev() assuming dummy_dev was allocated (but it was not), potentially causing a NULL pointer dereference. By moving free_netdev() to mtk_remove(), we ensure it's only called when mtk_probe() has succeeded and dummy_dev is fully allocated. This addresses a potential NULL pointer dereference detected by Smatch[1].

In the Linux kernel, the following vulnerability has been resolved: s390/mm: Add NULL pointer check to crst_table_free() base_crst_free() crst_table_free() used to work with NULL pointers before the conversion to ptdescs. Since crst_table_free() can be called with a NULL pointer (error handling in crst_table_upgrade() add an explicit check. Also add the same check to base_crst_free() for consistency reasons. In real life this should not happen, since order two GFP_KERNEL allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add NULL pointer check for kzalloc [Why & How] Check return pointer of kzalloc before using it.

In the Linux kernel, the following vulnerability has been resolved: fs: don't misleadingly warn during thaw operations The block device may have been frozen before it was claimed by a filesystem. Concurrently another process might try to mount that frozen block device and has temporarily claimed the block device for that purpose causing a concurrent fs_bdev_thaw() to end up here. The mounter is already about to abort mounting because they still saw an elevanted bdev->bd_fsfreeze_count so get_bdev_super() will return NULL in that case. For example, P1 calls dm_suspend() which calls into bdev_freeze() before the block device has been claimed by the filesystem. This brings bdev->bd_fsfreeze_count to 1 and no call into fs_bdev_freeze() is required. Now P2 tries to mount that frozen block device. It claims it and checks bdev->bd_fsfreeze_count. As it's elevated it aborts mounting. In the meantime P3 called dm_resume(). P3 sees that the block device is already claimed by a filesystem and calls into fs_bdev_thaw(). P3 takes a passive reference and realizes that the filesystem isn't ready yet. P3 puts itself to sleep to wait for the filesystem to become ready. P2 now puts the last active reference to the filesystem and marks it as dying. P3 gets woken, sees that the filesystem is dying and get_bdev_super() fails.