In the Linux kernel, the following vulnerability has been resolved: btrfs: fix error propagation of split bios The purpose of btrfs_bbio_propagate_error() shall be propagating an error of split bio to its original btrfs_bio, and tell the error to the upper layer. However, it's not working well on some cases. * Case 1. Immediate (or quick) end_bio with an error When btrfs sends btrfs_bio to mirrored devices, btrfs calls btrfs_bio_end_io() when all the mirroring bios are completed. If that btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error() accesses the orig_bbio's bio context to increase the error count. That works well in most cases. However, if the end_io is called enough fast, orig_bbio's (remaining part after split) bio context may not be properly set at that time. Since the bio context is set when the orig_bbio (the last btrfs_bio) is sent to devices, that might be too late for earlier split btrfs_bio's completion. That will result in NULL pointer dereference. That bug is easily reproducible by running btrfs/146 on zoned devices [1] and it shows the following trace. [1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ #474 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: writeback wb_workfn (flush-btrfs-5) RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs] BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0 RSP: 0018:ffffc9000006f248 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080 RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58 R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158 FS: 0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body.cold+0x19/0x26 ? page_fault_oops+0x13e/0x2b0 ? _printk+0x58/0x73 ? do_user_addr_fault+0x5f/0x750 ? exc_page_fault+0x76/0x240 ? asm_exc_page_fault+0x22/0x30 ? btrfs_bio_end_io+0xae/0xc0 [btrfs] ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs] btrfs_orig_write_end_io+0x51/0x90 [btrfs] dm_submit_bio+0x5c2/0xa50 [dm_mod] ? find_held_lock+0x2b/0x80 ? blk_try_enter_queue+0x90/0x1e0 __submit_bio+0xe0/0x130 ? ktime_get+0x10a/0x160 ? lockdep_hardirqs_on+0x74/0x100 submit_bio_noacct_nocheck+0x199/0x410 btrfs_submit_bio+0x7d/0x150 [btrfs] btrfs_submit_chunk+0x1a1/0x6d0 [btrfs] ? lockdep_hardirqs_on+0x74/0x100 ? __folio_start_writeback+0x10/0x2c0 btrfs_submit_bbio+0x1c/0x40 [btrfs] submit_one_bio+0x44/0x60 [btrfs] submit_extent_folio+0x13f/0x330 [btrfs] ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs] extent_writepage_io+0x18b/0x360 [btrfs] extent_write_locked_range+0x17c/0x340 [btrfs] ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs] run_delalloc_cow+0x71/0xd0 [btrfs] btrfs_run_delalloc_range+0x176/0x500 [btrfs] ? find_lock_delalloc_range+0x119/0x260 [btrfs] writepage_delalloc+0x2ab/0x480 [btrfs] extent_write_cache_pages+0x236/0x7d0 [btrfs] btrfs_writepages+0x72/0x130 [btrfs] do_writepages+0xd4/0x240 ? find_held_lock+0x2b/0x80 ? wbc_attach_and_unlock_inode+0x12c/0x290 ? wbc_attach_and_unlock_inode+0x12c/0x29 ---truncated---

A null pointer dereference vulnerability was found in ath10k_wmi_tlv_op_pull_mgmt_tx_compl_ev() in drivers/net/wireless/ath/ath10k/wmi-tlv.c in the Linux kernel. This issue could be exploited to trigger a denial of service.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check null pointer before dereferencing se [WHAT & HOW] se is null checked previously in the same function, indicating it might be null; therefore, it must be checked when used again. This fixes 1 FORWARD_NULL issue reported by Coverity.

In the Linux kernel, the following vulnerability has been resolved: net: hns3: fix kernel crash when uninstalling driver When the driver is uninstalled and the VF is disabled concurrently, a kernel crash occurs. The reason is that the two actions call function pci_disable_sriov(). The num_VFs is checked to determine whether to release the corresponding resources. During the second calling, num_VFs is not 0 and the resource release function is called. However, the corresponding resource has been released during the first invoking. Therefore, the problem occurs: [15277.839633][T50670] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... [15278.131557][T50670] Call trace: [15278.134686][T50670] klist_put+0x28/0x12c [15278.138682][T50670] klist_del+0x14/0x20 [15278.142592][T50670] device_del+0xbc/0x3c0 [15278.146676][T50670] pci_remove_bus_device+0x84/0x120 [15278.151714][T50670] pci_stop_and_remove_bus_device+0x6c/0x80 [15278.157447][T50670] pci_iov_remove_virtfn+0xb4/0x12c [15278.162485][T50670] sriov_disable+0x50/0x11c [15278.166829][T50670] pci_disable_sriov+0x24/0x30 [15278.171433][T50670] hnae3_unregister_ae_algo_prepare+0x60/0x90 [hnae3] [15278.178039][T50670] hclge_exit+0x28/0xd0 [hclge] [15278.182730][T50670] __se_sys_delete_module.isra.0+0x164/0x230 [15278.188550][T50670] __arm64_sys_delete_module+0x1c/0x30 [15278.193848][T50670] invoke_syscall+0x50/0x11c [15278.198278][T50670] el0_svc_common.constprop.0+0x158/0x164 [15278.203837][T50670] do_el0_svc+0x34/0xcc [15278.207834][T50670] el0_svc+0x20/0x30 For details, see the following figure. rmmod hclge disable VFs ---------------------------------------------------- hclge_exit() sriov_numvfs_store() ... device_lock() pci_disable_sriov() hns3_pci_sriov_configure() pci_disable_sriov() sriov_disable() sriov_disable() if !num_VFs : if !num_VFs : return; return; sriov_del_vfs() sriov_del_vfs() ... ... klist_put() klist_put() ... ... num_VFs = 0; num_VFs = 0; device_unlock(); In this patch, when driver is removing, we get the device_lock() to protect num_VFs, just like sriov_numvfs_store().

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: Fix ERR_PTR dereference in uvc_v4l2.c Fix potential dereferencing of ERR_PTR() in find_format_by_pix() and uvc_v4l2_enum_format(). Fix the following smatch errors: drivers/usb/gadget/function/uvc_v4l2.c:124 find_format_by_pix() error: 'fmtdesc' dereferencing possible ERR_PTR() drivers/usb/gadget/function/uvc_v4l2.c:392 uvc_v4l2_enum_format() error: 'fmtdesc' dereferencing possible ERR_PTR() Also, fix similar issue in uvc_v4l2_try_format() for potential dereferencing of ERR_PTR().

In the Linux kernel, the following vulnerability has been resolved: sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues efx->xdp_tx_queue_count is initially initialized to num_possible_cpus() and is later used to allocate and traverse efx->xdp_tx_queues lookup array. However, we may end up not initializing all the array slots with real queues during probing. This results, for example, in a NULL pointer dereference, when running "# ethtool -S <iface>", similar to below [2570283.664955][T4126959] BUG: kernel NULL pointer dereference, address: 00000000000000f8 [2570283.681283][T4126959] #PF: supervisor read access in kernel mode [2570283.695678][T4126959] #PF: error_code(0x0000) - not-present page [2570283.710013][T4126959] PGD 0 P4D 0 [2570283.721649][T4126959] Oops: 0000 [#1] SMP PTI [2570283.734108][T4126959] CPU: 23 PID: 4126959 Comm: ethtool Tainted: G O 5.10.20-cloudflare-2021.3.1 #1 [2570283.752641][T4126959] Hardware name: <redacted> [2570283.781408][T4126959] RIP: 0010:efx_ethtool_get_stats+0x2ca/0x330 [sfc] [2570283.796073][T4126959] Code: 00 85 c0 74 39 48 8b 95 a8 0f 00 00 48 85 d2 74 2d 31 c0 eb 07 48 8b 95 a8 0f 00 00 48 63 c8 49 83 c4 08 83 c0 01 48 8b 14 ca <48> 8b 92 f8 00 00 00 49 89 54 24 f8 39 85 a0 0f 00 00 77 d7 48 8b [2570283.831259][T4126959] RSP: 0018:ffffb79a77657ce8 EFLAGS: 00010202 [2570283.845121][T4126959] RAX: 0000000000000019 RBX: ffffb799cd0c9280 RCX: 0000000000000018 [2570283.860872][T4126959] RDX: 0000000000000000 RSI: ffff96dd970ce000 RDI: 0000000000000005 [2570283.876525][T4126959] RBP: ffff96dd86f0a000 R08: ffff96dd970ce480 R09: 000000000000005f [2570283.892014][T4126959] R10: ffffb799cd0c9fff R11: ffffb799cd0c9000 R12: ffffb799cd0c94f8 [2570283.907406][T4126959] R13: ffffffffc11b1090 R14: ffff96dd970ce000 R15: ffffffffc11cd66c [2570283.922705][T4126959] FS: 00007fa7723f8740(0000) GS:ffff96f51fac0000(0000) knlGS:0000000000000000 [2570283.938848][T4126959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [2570283.952524][T4126959] CR2: 00000000000000f8 CR3: 0000001a73e6e006 CR4: 00000000007706e0 [2570283.967529][T4126959] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [2570283.982400][T4126959] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [2570283.997308][T4126959] PKRU: 55555554 [2570284.007649][T4126959] Call Trace: [2570284.017598][T4126959] dev_ethtool+0x1832/0x2830 Fix this by adjusting efx->xdp_tx_queue_count after probing to reflect the true value of initialized slots in efx->xdp_tx_queues.

In the Linux kernel, the following vulnerability has been resolved: unicode: Fix utf8_load() error path utf8_load() requests the symbol "utf8_data_table" and then checks if the requested UTF-8 version is supported. If it's unsupported, it tries to put the data table using symbol_put(). If an unsupported version is requested, symbol_put() fails like this: kernel BUG at kernel/module/main.c:786! RIP: 0010:__symbol_put+0x93/0xb0 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x65/0x80 ? __symbol_put+0x93/0xb0 ? exc_invalid_op+0x51/0x70 ? __symbol_put+0x93/0xb0 ? asm_exc_invalid_op+0x1a/0x20 ? __pfx_cmp_name+0x10/0x10 ? __symbol_put+0x93/0xb0 ? __symbol_put+0x62/0xb0 utf8_load+0xf8/0x150 That happens because symbol_put() expects the unique string that identify the symbol, instead of a pointer to the loaded symbol. Fix that by using such string.

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad7606: check for NULL before calling sw_mode_config() Check that the sw_mode_config function pointer is not NULL before calling it. Not all buses define this callback, which resulted in a NULL pointer dereference.

A null pointer dereference vulnerability was found in dpll_pin_parent_pin_set() in drivers/dpll/dpll_netlink.c in the Digital Phase Locked Loop (DPLL) subsystem in the Linux kernel. This issue could be exploited to trigger a denial of service.

A Null pointer dereference problem was found in ida_free in lib/idr.c in the Linux Kernel. This issue may allow an attacker using this library to cause a denial of service problem due to a missing check at a function return.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check link_res->hpo_dp_link_enc before using it [WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing. This fixes 2 FORWARD_NULL issues reported by Coverity.

In the Linux kernel, the following vulnerability has been resolved: nfsd: call cache_put if xdr_reserve_space returns NULL If not enough buffer space available, but idmap_lookup has triggered lookup_fn which calls cache_get and returns successfully. Then we missed to call cache_put here which pairs with cache_get. Reviwed-by: Jeff Layton <jlayton@kernel.org>

In the Linux kernel, the following vulnerability has been resolved: driver: iio: add missing checks on iio_info's callback access Some callbacks from iio_info structure are accessed without any check, so if a driver doesn't implement them trying to access the corresponding sysfs entries produce a kernel oops such as: [ 2203.527791] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when execute [...] [ 2203.783416] Call trace: [ 2203.783429] iio_read_channel_info_avail from dev_attr_show+0x18/0x48 [ 2203.789807] dev_attr_show from sysfs_kf_seq_show+0x90/0x120 [ 2203.794181] sysfs_kf_seq_show from seq_read_iter+0xd0/0x4e4 [ 2203.798555] seq_read_iter from vfs_read+0x238/0x2a0 [ 2203.802236] vfs_read from ksys_read+0xa4/0xd4 [ 2203.805385] ksys_read from ret_fast_syscall+0x0/0x54 [ 2203.809135] Exception stack(0xe0badfa8 to 0xe0badff0) [ 2203.812880] dfa0: 00000003 b6f10f80 00000003 b6eab000 00020000 00000000 [ 2203.819746] dfc0: 00000003 b6f10f80 7ff00000 00000003 00000003 00000000 00020000 00000000 [ 2203.826619] dfe0: b6e1bc88 bed80958 b6e1bc94 b6e1bcb0 [ 2203.830363] Code: bad PC value [ 2203.832695] ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: added NULL check at start of dc_validate_stream [Why] prevent invalid memory access [How] check if dc and stream are NULL

In the Linux kernel, the following vulnerability has been resolved: i915/perf: Fix NULL deref bugs with drm_dbg() calls When i915 perf interface is not available dereferencing it will lead to NULL dereferences. As returning -ENOTSUPP is pretty clear return when perf interface is not available. [tursulin: added stable tag] (cherry picked from commit 36f27350ff745bd228ab04d7845dfbffc177a889)

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>

In the Linux kernel, the following vulnerability has been resolved: ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k.

In the Linux kernel, the following vulnerability has been resolved: scsi: hisi_sas: Grab sas_dev lock when traversing the members of sas_dev.list When freeing slots in function slot_complete_v3_hw(), it is possible that sas_dev.list is being traversed elsewhere, and it may trigger a NULL pointer exception, such as follows: ==>cq thread ==>scsi_eh_6 ==>scsi_error_handler() ==>sas_eh_handle_sas_errors() ==>sas_scsi_find_task() ==>lldd_abort_task() ==>slot_complete_v3_hw() ==>hisi_sas_abort_task() ==>hisi_sas_slot_task_free() ==>dereg_device_v3_hw() ==>list_del_init() ==>list_for_each_entry_safe() [ 7165.434918] sas: Enter sas_scsi_recover_host busy: 32 failed: 32 [ 7165.434926] sas: trying to find task 0x00000000769b5ba5 [ 7165.434927] sas: sas_scsi_find_task: aborting task 0x00000000769b5ba5 [ 7165.434940] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000769b5ba5) aborted [ 7165.434964] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000c9f7aa07) ignored [ 7165.434965] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(00000000e2a1cf01) ignored [ 7165.434968] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 7165.434972] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(0000000022d52d93) ignored [ 7165.434975] hisi_sas_v3_hw 0000:b4:02.0: slot complete: task(0000000066a7516c) ignored [ 7165.434976] Mem abort info: [ 7165.434982] ESR = 0x96000004 [ 7165.434991] Exception class = DABT (current EL), IL = 32 bits [ 7165.434992] SET = 0, FnV = 0 [ 7165.434993] EA = 0, S1PTW = 0 [ 7165.434994] Data abort info: [ 7165.434994] ISV = 0, ISS = 0x00000004 [ 7165.434995] CM = 0, WnR = 0 [ 7165.434997] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f29543f2 [ 7165.434998] [0000000000000000] pgd=0000000000000000 [ 7165.435003] Internal error: Oops: 96000004 [#1] SMP [ 7165.439863] Process scsi_eh_6 (pid: 4109, stack limit = 0x00000000c43818d5) [ 7165.468862] pstate: 00c00009 (nzcv daif +PAN +UAO) [ 7165.473637] pc : dereg_device_v3_hw+0x68/0xa8 [hisi_sas_v3_hw] [ 7165.479443] lr : dereg_device_v3_hw+0x2c/0xa8 [hisi_sas_v3_hw] [ 7165.485247] sp : ffff00001d623bc0 [ 7165.488546] x29: ffff00001d623bc0 x28: ffffa027d03b9508 [ 7165.493835] x27: ffff80278ed50af0 x26: ffffa027dd31e0a8 [ 7165.499123] x25: ffffa027d9b27f88 x24: ffffa027d9b209f8 [ 7165.504411] x23: ffffa027c45b0d60 x22: ffff80278ec07c00 [ 7165.509700] x21: 0000000000000008 x20: ffffa027d9b209f8 [ 7165.514988] x19: ffffa027d9b27f88 x18: ffffffffffffffff [ 7165.520276] x17: 0000000000000000 x16: 0000000000000000 [ 7165.525564] x15: ffff0000091d9708 x14: ffff0000093b7dc8 [ 7165.530852] x13: ffff0000093b7a23 x12: 6e7265746e692067 [ 7165.536140] x11: 0000000000000000 x10: 0000000000000bb0 [ 7165.541429] x9 : ffff00001d6238f0 x8 : ffffa027d877af00 [ 7165.546718] x7 : ffffa027d6329600 x6 : ffff7e809f58ca00 [ 7165.552006] x5 : 0000000000001f8a x4 : 000000000000088e [ 7165.557295] x3 : ffffa027d9b27fa8 x2 : 0000000000000000 [ 7165.562583] x1 : 0000000000000000 x0 : 000000003000188e [ 7165.567872] Call trace: [ 7165.570309] dereg_device_v3_hw+0x68/0xa8 [hisi_sas_v3_hw] [ 7165.575775] hisi_sas_abort_task+0x248/0x358 [hisi_sas_main] [ 7165.581415] sas_eh_handle_sas_errors+0x258/0x8e0 [libsas] [ 7165.586876] sas_scsi_recover_host+0x134/0x458 [libsas] [ 7165.592082] scsi_error_handler+0xb4/0x488 [ 7165.596163] kthread+0x134/0x138 [ 7165.599380] ret_from_fork+0x10/0x18 [ 7165.602940] Code: d5033e9f b9000040 aa0103e2 eb03003f (f9400021) [ 7165.609004] kernel fault(0x1) notification starting on CPU 75 [ 7165.700728] ---[ end trace fc042cbbea224efc ]--- [ 7165.705326] Kernel panic - not syncing: Fatal exception To fix the issue, grab sas_dev lock when traversing the members of sas_dev.list in dereg_device_v3_hw() and hisi_sas_release_tasks() to avoid concurrency of adding and deleting member. When ---truncated---

In the Linux kernel, the following vulnerability has been resolved: null_blk: fix poll request timeout handling When doing io_uring benchmark on /dev/nullb0, it's easy to crash the kernel if poll requests timeout triggered, as reported by David. [1] BUG: kernel NULL pointer dereference, address: 0000000000000008 Workqueue: kblockd blk_mq_timeout_work RIP: 0010:null_timeout_rq+0x4e/0x91 Call Trace: ? null_timeout_rq+0x4e/0x91 blk_mq_handle_expired+0x31/0x4b bt_iter+0x68/0x84 ? bt_tags_iter+0x81/0x81 __sbitmap_for_each_set.constprop.0+0xb0/0xf2 ? __blk_mq_complete_request_remote+0xf/0xf bt_for_each+0x46/0x64 ? __blk_mq_complete_request_remote+0xf/0xf ? percpu_ref_get_many+0xc/0x2a blk_mq_queue_tag_busy_iter+0x14d/0x18e blk_mq_timeout_work+0x95/0x127 process_one_work+0x185/0x263 worker_thread+0x1b5/0x227 This is indeed a race problem between null_timeout_rq() and null_poll(). null_poll() null_timeout_rq() spin_lock(&nq->poll_lock) list_splice_init(&nq->poll_list, &list) spin_unlock(&nq->poll_lock) while (!list_empty(&list)) req = list_first_entry() list_del_init() ... blk_mq_add_to_batch() // req->rq_next = NULL spin_lock(&nq->poll_lock) // rq->queuelist->next == NULL list_del_init(&rq->queuelist) spin_unlock(&nq->poll_lock) Fix these problems by setting requests state to MQ_RQ_COMPLETE under nq->poll_lock protection, in which null_timeout_rq() can safely detect this race and early return. Note this patch just fix the kernel panic when request timeout happen. [1] https://lore.kernel.org/all/3893581.1691785261@warthog.procyon.org.uk/

In the Linux kernel, the following vulnerability has been resolved: fscrypt: destroy keyring after security_sb_delete() fscrypt_destroy_keyring() must be called after all potentially-encrypted inodes were evicted; otherwise it cannot safely destroy the keyring. Since inodes that are in-use by the Landlock LSM don't get evicted until security_sb_delete(), this means that fscrypt_destroy_keyring() must be called *after* security_sb_delete(). This fixes a WARN_ON followed by a NULL dereference, only possible if Landlock was being used on encrypted files.

In the Linux kernel, the following vulnerability has been resolved: pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv The hotplug driver for powerpc (pci/hotplug/pnv_php.c) causes a kernel crash when we try to hot-unplug/disable the PCIe switch/bridge from the PHB. The crash occurs because although the MSI data structure has been released during disable/hot-unplug path and it has been assigned with NULL, still during unregistration the code was again trying to explicitly disable the MSI which causes the NULL pointer dereference and kernel crash. The patch fixes the check during unregistration path to prevent invoking pci_disable_msi/msix() since its data structure is already freed.

In the Linux kernel, the following vulnerability has been resolved: media: pci: tw68: Fix null-ptr-deref bug in buf prepare and finish When the driver calls tw68_risc_buffer() to prepare the buffer, the function call dma_alloc_coherent may fail, resulting in a empty buffer buf->cpu. Later when we free the buffer or access the buffer, null ptr deref is triggered. This bug is similar to the following one: https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71. We believe the bug can be also dynamically triggered from user side. Similarly, we fix this by checking the return value of tw68_risc_buffer() and the value of buf->cpu before buffer free.

In the Linux kernel, the following vulnerability has been resolved: video/aperture: optionally match the device in sysfb_disable() In aperture_remove_conflicting_pci_devices(), we currently only call sysfb_disable() on vga class devices. This leads to the following problem when the pimary device is not VGA compatible: 1. A PCI device with a non-VGA class is the boot display 2. That device is probed first and it is not a VGA device so sysfb_disable() is not called, but the device resources are freed by aperture_detach_platform_device() 3. Non-primary GPU has a VGA class and it ends up calling sysfb_disable() 4. NULL pointer dereference via sysfb_disable() since the resources have already been freed by aperture_detach_platform_device() when it was called by the other device. Fix this by passing a device pointer to sysfb_disable() and checking the device to determine if we should execute it or not. v2: Fix build when CONFIG_SCREEN_INFO is not set v3: Move device check into the mutex Drop primary variable in aperture_remove_conflicting_pci_devices() Drop __init on pci sysfb_pci_dev_is_enabled()

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate() In Google internal bug 265639009 we've received an (as yet) unreproducible crash report from an aarch64 GKI 5.10.149-android13 running device. AFAICT the source code is at: https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10 The call stack is: ncm_close() -> ncm_notify() -> ncm_do_notify() with the crash at: ncm_do_notify+0x98/0x270 Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b) Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...): // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification) 0B 0D 00 79 strh w11, [x8, #6] // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request) 6C 0A 00 B9 str w12, [x19, #8] // x10 (NULL) was read here from offset 0 of valid pointer x9 // IMHO we're reading 'cdev->gadget' and getting NULL // gadget is indeed at offset 0 of struct usb_composite_dev 2A 01 40 F9 ldr x10, [x9] // loading req->buf pointer, which is at offset 0 of struct usb_request 69 02 40 F9 ldr x9, [x19] // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed 4B 5D 40 B9 ldr w11, [x10, #0x5c] which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment: event->wLength = cpu_to_le16(8); req->length = NCM_STATUS_BYTECOUNT; /* SPEED_CHANGE data is up/down speeds in bits/sec */ data = req->buf + sizeof *event; data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); My analysis of registers and NULL ptr deref crash offset (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c) heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing: data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); which calls: ncm_bitrate(NULL) which then calls: gadget_is_superspeed(NULL) which reads ((struct usb_gadget *)NULL)->max_speed and hits a panic. AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C. (remember there's a GKI KABI reservation of 16 bytes in struct work_struct) It's not at all clear to me how this is all supposed to work... but returning 0 seems much better than panic-ing...

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt7629-eth: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6797: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential NULL dereference Fix potential NULL dereference, in the case when "man", the resource manager might be NULL, when/if we print debug information.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: E-Switch, Fix an Oops in error handling code The error handling dereferences "vport". There is nothing we can do if it is an error pointer except returning the error code.

In the Linux kernel, the following vulnerability has been resolved: bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent In some specific situations, the return value of __bch_btree_node_alloc may be NULL. This may lead to a potential NULL pointer dereference in caller function like a calling chain : btree_split->bch_btree_node_alloc->__bch_btree_node_alloc. Fix it by initializing the return value in __bch_btree_node_alloc.

In the Linux kernel, the following vulnerability has been resolved: apparmor: Fix null pointer deref when receiving skb during sock creation The panic below is observed when receiving ICMP packets with secmark set while an ICMP raw socket is being created. SK_CTX(sk)->label is updated in apparmor_socket_post_create(), but the packet is delivered to the socket before that, causing the null pointer dereference. Drop the packet if label context is not set. BUG: kernel NULL pointer dereference, address: 000000000000004c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 407 Comm: a.out Not tainted 6.4.12-arch1-1 #1 3e6fa2753a2d75925c34ecb78e22e85a65d083df Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/28/2020 RIP: 0010:aa_label_next_confined+0xb/0x40 Code: 00 00 48 89 ef e8 d5 25 0c 00 e9 66 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 89 f0 <8b> 77 4c 39 c6 7e 1f 48 63 d0 48 8d 14 d7 eb 0b 83 c0 01 48 83 c2 RSP: 0018:ffffa92940003b08 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000000e RDX: ffffa92940003be8 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8b57471e7800 R08: ffff8b574c642400 R09: 0000000000000002 R10: ffffffffbd820eeb R11: ffffffffbeb7ff00 R12: ffff8b574c642400 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 FS: 00007fb092ea7640(0000) GS:ffff8b577bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000004c CR3: 00000001020f2005 CR4: 00000000007706f0 PKRU: 55555554 Call Trace: <IRQ> ? __die+0x23/0x70 ? page_fault_oops+0x171/0x4e0 ? exc_page_fault+0x7f/0x180 ? asm_exc_page_fault+0x26/0x30 ? aa_label_next_confined+0xb/0x40 apparmor_secmark_check+0xec/0x330 security_sock_rcv_skb+0x35/0x50 sk_filter_trim_cap+0x47/0x250 sock_queue_rcv_skb_reason+0x20/0x60 raw_rcv+0x13c/0x210 raw_local_deliver+0x1f3/0x250 ip_protocol_deliver_rcu+0x4f/0x2f0 ip_local_deliver_finish+0x76/0xa0 __netif_receive_skb_one_core+0x89/0xa0 netif_receive_skb+0x119/0x170 ? __netdev_alloc_skb+0x3d/0x140 vmxnet3_rq_rx_complete+0xb23/0x1010 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a] vmxnet3_poll_rx_only+0x36/0xb0 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a] __napi_poll+0x28/0x1b0 net_rx_action+0x2a4/0x380 __do_softirq+0xd1/0x2c8 __irq_exit_rcu+0xbb/0xf0 common_interrupt+0x86/0xa0 </IRQ> <TASK> asm_common_interrupt+0x26/0x40 RIP: 0010:apparmor_socket_post_create+0xb/0x200 Code: 08 48 85 ff 75 a1 eb b1 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 <55> 48 89 fd 53 45 85 c0 0f 84 b2 00 00 00 48 8b 1d 80 56 3f 02 48 RSP: 0018:ffffa92940ce7e50 EFLAGS: 00000286 RAX: ffffffffbc756440 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000003 RSI: 0000000000000002 RDI: ffff8b574eaab740 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8b57444cec70 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000002 R14: ffff8b574eaab740 R15: ffffffffbd8e4748 ? __pfx_apparmor_socket_post_create+0x10/0x10 security_socket_post_create+0x4b/0x80 __sock_create+0x176/0x1f0 __sys_socket+0x89/0x100 __x64_sys_socket+0x17/0x20 do_syscall_64+0x5d/0x90 ? do_syscall_64+0x6c/0x90 ? do_syscall_64+0x6c/0x90 ? do_syscall_64+0x6c/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc

In the Linux kernel, the following vulnerability has been resolved: dm stats: check for and propagate alloc_percpu failure Check alloc_precpu()'s return value and return an error from dm_stats_init() if it fails. Update alloc_dev() to fail if dm_stats_init() does. Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup() even if dm-stats isn't being actively used.

In the Linux kernel, the following vulnerability has been resolved: ice: xsk: disable txq irq before flushing hw ice_qp_dis() intends to stop a given queue pair that is a target of xsk pool attach/detach. One of the steps is to disable interrupts on these queues. It currently is broken in a way that txq irq is turned off *after* HW flush which in turn takes no effect. ice_qp_dis(): -> ice_qvec_dis_irq() --> disable rxq irq --> flush hw -> ice_vsi_stop_tx_ring() -->disable txq irq Below splat can be triggered by following steps: - start xdpsock WITHOUT loading xdp prog - run xdp_rxq_info with XDP_TX action on this interface - start traffic - terminate xdpsock [ 256.312485] BUG: kernel NULL pointer dereference, address: 0000000000000018 [ 256.319560] #PF: supervisor read access in kernel mode [ 256.324775] #PF: error_code(0x0000) - not-present page [ 256.329994] PGD 0 P4D 0 [ 256.332574] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 256.337006] CPU: 3 PID: 32 Comm: ksoftirqd/3 Tainted: G OE 6.2.0-rc5+ #51 [ 256.345218] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [ 256.355807] RIP: 0010:ice_clean_rx_irq_zc+0x9c/0x7d0 [ice] [ 256.361423] Code: b7 8f 8a 00 00 00 66 39 ca 0f 84 f1 04 00 00 49 8b 47 40 4c 8b 24 d0 41 0f b7 45 04 66 25 ff 3f 66 89 04 24 0f 84 85 02 00 00 <49> 8b 44 24 18 0f b7 14 24 48 05 00 01 00 00 49 89 04 24 49 89 44 [ 256.380463] RSP: 0018:ffffc900088bfd20 EFLAGS: 00010206 [ 256.385765] RAX: 000000000000003c RBX: 0000000000000035 RCX: 000000000000067f [ 256.393012] RDX: 0000000000000775 RSI: 0000000000000000 RDI: ffff8881deb3ac80 [ 256.400256] RBP: 000000000000003c R08: ffff889847982710 R09: 0000000000010000 [ 256.407500] R10: ffffffff82c060c0 R11: 0000000000000004 R12: 0000000000000000 [ 256.414746] R13: ffff88811165eea0 R14: ffffc9000d255000 R15: ffff888119b37600 [ 256.421990] FS: 0000000000000000(0000) GS:ffff8897e0cc0000(0000) knlGS:0000000000000000 [ 256.430207] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 256.436036] CR2: 0000000000000018 CR3: 0000000005c0a006 CR4: 00000000007706e0 [ 256.443283] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 256.450527] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 256.457770] PKRU: 55555554 [ 256.460529] Call Trace: [ 256.463015] <TASK> [ 256.465157] ? ice_xmit_zc+0x6e/0x150 [ice] [ 256.469437] ice_napi_poll+0x46d/0x680 [ice] [ 256.473815] ? _raw_spin_unlock_irqrestore+0x1b/0x40 [ 256.478863] __napi_poll+0x29/0x160 [ 256.482409] net_rx_action+0x136/0x260 [ 256.486222] __do_softirq+0xe8/0x2e5 [ 256.489853] ? smpboot_thread_fn+0x2c/0x270 [ 256.494108] run_ksoftirqd+0x2a/0x50 [ 256.497747] smpboot_thread_fn+0x1c1/0x270 [ 256.501907] ? __pfx_smpboot_thread_fn+0x10/0x10 [ 256.506594] kthread+0xea/0x120 [ 256.509785] ? __pfx_kthread+0x10/0x10 [ 256.513597] ret_from_fork+0x29/0x50 [ 256.517238] </TASK> In fact, irqs were not disabled and napi managed to be scheduled and run while xsk_pool pointer was still valid, but SW ring of xdp_buff pointers was already freed. To fix this, call ice_qvec_dis_irq() after ice_vsi_stop_tx_ring(). Also while at it, remove redundant ice_clean_rx_ring() call - this is handled in ice_qp_clean_rings().

In the Linux kernel, the following vulnerability has been resolved: hid: cp2112: Fix duplicate workqueue initialization Previously the cp2112 driver called INIT_DELAYED_WORK within cp2112_gpio_irq_startup, resulting in duplicate initilizations of the workqueue on subsequent IRQ startups following an initial request. This resulted in a warning in set_work_data in workqueue.c, as well as a rare NULL dereference within process_one_work in workqueue.c. Initialize the workqueue within _probe instead.

In the Linux kernel, the following vulnerability has been resolved: media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish() When the driver calls cx23885_risc_buffer() to prepare the buffer, the function call dma_alloc_coherent may fail, resulting in a empty buffer risc->cpu. Later when we free the buffer or access the buffer, null ptr deref is triggered. This bug is similar to the following one: https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71. We believe the bug can be also dynamically triggered from user side. Similarly, we fix this by checking the return value of cx23885_risc_buffer() and the value of risc->cpu before buffer free.

In the Linux kernel, the following vulnerability has been resolved: nfc: fdp: add null check of devm_kmalloc_array in fdp_nci_i2c_read_device_properties devm_kmalloc_array may fails, *fw_vsc_cfg might be null and cause out-of-bounds write in device_property_read_u8_array later.

In the Linux kernel, the following vulnerability has been resolved: media: az6007: Fix null-ptr-deref in az6007_i2c_xfer() In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach az6007_i2c_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

In the Linux kernel, the following vulnerability has been resolved: ACPI: processor: Check for null return of devm_kzalloc() in fch_misc_setup() devm_kzalloc() may fail, clk_data->name might be NULL and will cause a NULL pointer dereference later. [ rjw: Subject and changelog edits ]

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Add null pointer check in gserial_resume Consider a case where gserial_disconnect has already cleared gser->ioport. And if a wakeup interrupt triggers afterwards, gserial_resume gets called, which will lead to accessing of gser->ioport and thus causing null pointer dereference.Add a null pointer check to prevent this. Added a static spinlock to prevent gser->ioport from becoming null after the newly added check.

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus_core) Fix NULL pointer dereference Pass i2c_client to _pmbus_is_enabled to drop the assumption that a regulator device is passed in. This will fix the issue of a NULL pointer dereference when called from _pmbus_get_flags.

In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix shutdown order Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds.

In the Linux kernel, the following vulnerability has been resolved: bpf: support non-r10 register spill/fill to/from stack in precision tracking Use instruction (jump) history to record instructions that performed register spill/fill to/from stack, regardless if this was done through read-only r10 register, or any other register after copying r10 into it *and* potentially adjusting offset. To make this work reliably, we push extra per-instruction flags into instruction history, encoding stack slot index (spi) and stack frame number in extra 10 bit flags we take away from prev_idx in instruction history. We don't touch idx field for maximum performance, as it's checked most frequently during backtracking. This change removes basically the last remaining practical limitation of precision backtracking logic in BPF verifier. It fixes known deficiencies, but also opens up new opportunities to reduce number of verified states, explored in the subsequent patches. There are only three differences in selftests' BPF object files according to veristat, all in the positive direction (less states). File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF) -------------------------------------- ------------- --------- --------- ------------- ---------- ---------- ------------- test_cls_redirect_dynptr.bpf.linked3.o cls_redirect 2987 2864 -123 (-4.12%) 240 231 -9 (-3.75%) xdp_synproxy_kern.bpf.linked3.o syncookie_tc 82848 82661 -187 (-0.23%) 5107 5073 -34 (-0.67%) xdp_synproxy_kern.bpf.linked3.o syncookie_xdp 85116 84964 -152 (-0.18%) 5162 5130 -32 (-0.62%) Note, I avoided renaming jmp_history to more generic insn_hist to minimize number of lines changed and potential merge conflicts between bpf and bpf-next trees. Notice also cur_hist_entry pointer reset to NULL at the beginning of instruction verification loop. This pointer avoids the problem of relying on last jump history entry's insn_idx to determine whether we already have entry for current instruction or not. It can happen that we added jump history entry because current instruction is_jmp_point(), but also we need to add instruction flags for stack access. In this case, we don't want to entries, so we need to reuse last added entry, if it is present. Relying on insn_idx comparison has the same ambiguity problem as the one that was fixed recently in [0], so we avoid that. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20231110002638.4168352-3-andrii@kernel.org/

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Add null pointer check in gserial_suspend Consider a case where gserial_disconnect has already cleared gser->ioport. And if gserial_suspend gets called afterwards, it will lead to accessing of gser->ioport and thus causing null pointer dereference. Avoid this by adding a null pointer check. Added a static spinlock to prevent gser->ioport from becoming null after the newly added null pointer check.

In the Linux kernel, the following vulnerability has been resolved: FS: JFS: Fix null-ptr-deref Read in txBegin Syzkaller reported an issue where txBegin may be called on a superblock in a read-only mounted filesystem which leads to NULL pointer deref. This could be solved by checking if the filesystem is read-only before calling txBegin, and returning with appropiate error code.

In the Linux kernel, the following vulnerability has been resolved: media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer() In dw2102_i2c_transfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach dw2102_i2c_transfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 950e252cb469 ("[media] dw2102: limit messages to buffer size")

In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency In _dwc2_hcd_urb_enqueue(), "urb->hcpriv = NULL" is executed without holding the lock "hsotg->lock". In _dwc2_hcd_urb_dequeue(): spin_lock_irqsave(&hsotg->lock, flags); ... if (!urb->hcpriv) { dev_dbg(hsotg->dev, "## urb->hcpriv is NULL ##\n"); goto out; } rc = dwc2_hcd_urb_dequeue(hsotg, urb->hcpriv); // Use urb->hcpriv ... out: spin_unlock_irqrestore(&hsotg->lock, flags); When _dwc2_hcd_urb_enqueue() and _dwc2_hcd_urb_dequeue() are concurrently executed, the NULL check of "urb->hcpriv" can be executed before "urb->hcpriv = NULL". After urb->hcpriv is NULL, it can be used in the function call to dwc2_hcd_urb_dequeue(), which can cause a NULL pointer dereference. This possible bug is found by an experimental static analysis tool developed by myself. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. The above possible bug is reported, when my tool analyzes the source code of Linux 6.5. To fix this possible bug, "urb->hcpriv = NULL" should be executed with holding the lock "hsotg->lock". After using this patch, my tool never reports the possible bug, with the kernelconfiguration allyesconfig for x86_64. Because I have no associated hardware, I cannot test the patch in runtime testing, and just verify it according to the code logic.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: install stub fence into potential unused fence pointers When using cpu to update page tables, vm update fences are unused. Install stub fence into these fence pointers instead of NULL to avoid NULL dereference when calling dma_fence_wait() on them.

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: cfg80211: Handle SSID based pmksa deletion wpa_supplicant 2.11 sends since 1efdba5fdc2c ("Handle PMKSA flush in the driver for SAE/OWE offload cases") SSID based PMKSA del commands. brcmfmac is not prepared and tries to dereference the NULL bssid and pmkid pointers in cfg80211_pmksa. PMKID_V3 operations support SSID based updates so copy the SSID.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/mdp5: Add check for kzalloc As kzalloc may fail and return NULL pointer, it should be better to check the return value in order to avoid the NULL pointer dereference. Patchwork: https://patchwork.freedesktop.org/patch/514154/

In the Linux kernel, the following vulnerability has been resolved: drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug callbacks after the device has been unregistered, leading to fireworks when we try to execute empty function callbacks within the driver: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G W O 5.12.0-rc4+ #1 | Hardware name: , BIOS KpxxxFPGA 1P B600 V143 04/22/2021 | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) | pc : perf_pmu_migrate_context+0x98/0x38c | lr : perf_pmu_migrate_context+0x94/0x38c | | Call trace: | perf_pmu_migrate_context+0x98/0x38c | hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu] Use cpuhp_state_remove_instance_nocalls() instead of cpuhp_state_remove_instance() so that the notifiers don't execute after the PMU device has been unregistered. [will: Rewrote commit message]

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Check endpoint is valid before dereferencing it When the host controller is not responding, all URBs queued to all endpoints need to be killed. This can cause a kernel panic if we dereference an invalid endpoint. Fix this by using xhci_get_virt_ep() helper to find the endpoint and checking if the endpoint is valid before dereferencing it. [233311.853271] xhci-hcd xhci-hcd.1.auto: xHCI host controller not responding, assume dead [233311.853393] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8 [233311.853964] pc : xhci_hc_died+0x10c/0x270 [233311.853971] lr : xhci_hc_died+0x1ac/0x270 [233311.854077] Call trace: [233311.854085] xhci_hc_died+0x10c/0x270 [233311.854093] xhci_stop_endpoint_command_watchdog+0x100/0x1a4 [233311.854105] call_timer_fn+0x50/0x2d4 [233311.854112] expire_timers+0xac/0x2e4 [233311.854118] run_timer_softirq+0x300/0xabc [233311.854127] __do_softirq+0x148/0x528 [233311.854135] irq_exit+0x194/0x1a8 [233311.854143] __handle_domain_irq+0x164/0x1d0 [233311.854149] gic_handle_irq.22273+0x10c/0x188 [233311.854156] el1_irq+0xfc/0x1a8 [233311.854175] lpm_cpuidle_enter+0x25c/0x418 [msm_pm] [233311.854185] cpuidle_enter_state+0x1f0/0x764 [233311.854194] do_idle+0x594/0x6ac [233311.854201] cpu_startup_entry+0x7c/0x80 [233311.854209] secondary_start_kernel+0x170/0x198