In the Linux kernel, the following vulnerability has been resolved: jffs2: check that raw node were preallocated before writing summary Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't check return value of jffs2_prealloc_raw_node_refs and simply lets any error propagate into jffs2_sum_write_data, which eventually calls jffs2_link_node_ref in order to link the summary to an expectedly allocated node. kernel BUG at fs/jffs2/nodelist.c:592! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592 Call Trace: <TASK> jffs2_sum_write_data fs/jffs2/summary.c:841 [inline] jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735 do_iter_write+0x186/0x710 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:950 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896 do_splice_direct+0x1a9/0x280 fs/splice.c:1002 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Fix this issue by checking return value of jffs2_prealloc_raw_node_refs before calling jffs2_sum_write_data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() The function mod_hdcp_hdcp1_create_session() calls the function get_first_active_display(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference. Add a null pointer check for get_first_active_display() and return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null. This is similar to the commit c3e9826a2202 ("drm/amd/display: Add null pointer check for get_first_active_display()"). (cherry picked from commit 5e43eb3cd731649c4f8b9134f857be62a416c893)

In the Linux kernel, the following vulnerability has been resolved: drm/msm/gpu: Fix crash when throttling GPU immediately during boot There is a small chance that the GPU is already hot during boot. In that case, the call to of_devfreq_cooling_register() will immediately try to apply devfreq cooling, as seen in the following crash: Unable to handle kernel paging request at virtual address 0000000000014110 pc : a6xx_gpu_busy+0x1c/0x58 [msm] lr : msm_devfreq_get_dev_status+0xbc/0x140 [msm] Call trace: a6xx_gpu_busy+0x1c/0x58 [msm] (P) devfreq_simple_ondemand_func+0x3c/0x150 devfreq_update_target+0x44/0xd8 qos_max_notifier_call+0x30/0x84 blocking_notifier_call_chain+0x6c/0xa0 pm_qos_update_target+0xd0/0x110 freq_qos_apply+0x3c/0x74 apply_constraint+0x88/0x148 __dev_pm_qos_update_request+0x7c/0xcc dev_pm_qos_update_request+0x38/0x5c devfreq_cooling_set_cur_state+0x98/0xf0 __thermal_cdev_update+0x64/0xb4 thermal_cdev_update+0x4c/0x58 step_wise_manage+0x1f0/0x318 __thermal_zone_device_update+0x278/0x424 __thermal_cooling_device_register+0x2bc/0x308 thermal_of_cooling_device_register+0x10/0x1c of_devfreq_cooling_register_power+0x240/0x2bc of_devfreq_cooling_register+0x14/0x20 msm_devfreq_init+0xc4/0x1a0 [msm] msm_gpu_init+0x304/0x574 [msm] adreno_gpu_init+0x1c4/0x2e0 [msm] a6xx_gpu_init+0x5c8/0x9c8 [msm] adreno_bind+0x2a8/0x33c [msm] ... At this point we haven't initialized the GMU at all yet, so we cannot read the GMU registers inside a6xx_gpu_busy(). A similar issue was fixed before in commit 6694482a70e9 ("drm/msm: Avoid unclocked GMU register access in 6xx gpu_busy"): msm_devfreq_init() does call devfreq_suspend_device(), but unlike msm_devfreq_suspend(), it doesn't set the df->suspended flag accordingly. This means the df->suspended flag does not match the actual devfreq state after initialization and msm_devfreq_get_dev_status() will end up accessing GMU registers, causing the crash. Fix this by setting df->suspended correctly during initialization. Patchwork: https://patchwork.freedesktop.org/patch/650772/

In the Linux kernel, the following vulnerability has been resolved: net: appletalk: Fix device refcount leak in atrtr_create() When updating an existing route entry in atrtr_create(), the old device reference was not being released before assigning the new device, leading to a device refcount leak. Fix this by calling dev_put() to release the old device reference before holding the new one.

In the Linux kernel, the following vulnerability has been resolved: tipc: fix null-ptr-deref when acquiring remote ip of ethernet bearer The reproduction steps: 1. create a tun interface 2. enable l2 bearer 3. TIPC_NL_UDP_GET_REMOTEIP with media name set to tun tipc: Started in network mode tipc: Node identity 8af312d38a21, cluster identity 4711 tipc: Enabled bearer <eth:syz_tun>, priority 1 Oops: general protection fault KASAN: null-ptr-deref in range CPU: 1 UID: 1000 PID: 559 Comm: poc Not tainted 6.16.0-rc1+ #117 PREEMPT Hardware name: QEMU Ubuntu 24.04 PC RIP: 0010:tipc_udp_nl_dump_remoteip+0x4a4/0x8f0 the ub was in fact a struct dev. when bid != 0 && skip_cnt != 0, bearer_list[bid] may be NULL or other media when other thread changes it. fix this by checking media_id.

In the Linux kernel, the following vulnerability has been resolved: clk: bcm: rpi: Add NULL check in raspberrypi_clk_register() devm_kasprintf() returns NULL when memory allocation fails. Currently, raspberrypi_clk_register() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue.

In the Linux kernel, the following vulnerability has been resolved: hfsplus: don't use BUG_ON() in hfsplus_create_attributes_file() When the volume header contains erroneous values that do not reflect the actual state of the filesystem, hfsplus_fill_super() assumes that the attributes file is not yet created, which later results in hitting BUG_ON() when hfsplus_create_attributes_file() is called. Replace this BUG_ON() with -EIO error with a message to suggest running fsck tool.

Qemu has integer overflows because IOReadHandler and its associated functions use a signed integer data type for a size value.

In the Linux kernel, the following vulnerability has been resolved: crypto: sun8i-ce-cipher - fix error handling in sun8i_ce_cipher_prepare() Fix two DMA cleanup issues on the error path in sun8i_ce_cipher_prepare(): 1] If dma_map_sg() fails for areq->dst, the device driver would try to free DMA memory it has not allocated in the first place. To fix this, on the "theend_sgs" error path, call dma unmap only if the corresponding dma map was successful. 2] If the dma_map_single() call for the IV fails, the device driver would try to free an invalid DMA memory address on the "theend_iv" path: ------------[ cut here ]------------ DMA-API: sun8i-ce 1904000.crypto: device driver tries to free an invalid DMA memory address WARNING: CPU: 2 PID: 69 at kernel/dma/debug.c:968 check_unmap+0x123c/0x1b90 Modules linked in: skcipher_example(O+) CPU: 2 UID: 0 PID: 69 Comm: 1904000.crypto- Tainted: G O 6.15.0-rc3+ #24 PREEMPT Tainted: [O]=OOT_MODULE Hardware name: OrangePi Zero2 (DT) pc : check_unmap+0x123c/0x1b90 lr : check_unmap+0x123c/0x1b90 ... Call trace: check_unmap+0x123c/0x1b90 (P) debug_dma_unmap_page+0xac/0xc0 dma_unmap_page_attrs+0x1f4/0x5fc sun8i_ce_cipher_do_one+0x1bd4/0x1f40 crypto_pump_work+0x334/0x6e0 kthread_worker_fn+0x21c/0x438 kthread+0x374/0x664 ret_from_fork+0x10/0x20 ---[ end trace 0000000000000000 ]--- To fix this, check for !dma_mapping_error() before calling dma_unmap_single() on the "theend_iv" path.

In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Fix out-of-bound memcpy() during ethtool -w When retrieving the FW coredump using ethtool, it can sometimes cause memory corruption: BUG: KFENCE: memory corruption in __bnxt_get_coredump+0x3ef/0x670 [bnxt_en] Corrupted memory at 0x000000008f0f30e8 [ ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ] (in kfence-#45): __bnxt_get_coredump+0x3ef/0x670 [bnxt_en] ethtool_get_dump_data+0xdc/0x1a0 __dev_ethtool+0xa1e/0x1af0 dev_ethtool+0xa8/0x170 dev_ioctl+0x1b5/0x580 sock_do_ioctl+0xab/0xf0 sock_ioctl+0x1ce/0x2e0 __x64_sys_ioctl+0x87/0xc0 do_syscall_64+0x5c/0xf0 entry_SYSCALL_64_after_hwframe+0x78/0x80 ... This happens when copying the coredump segment list in bnxt_hwrm_dbg_dma_data() with the HWRM_DBG_COREDUMP_LIST FW command. The info->dest_buf buffer is allocated based on the number of coredump segments returned by the FW. The segment list is then DMA'ed by the FW and the length of the DMA is returned by FW. The driver then copies this DMA'ed segment list to info->dest_buf. In some cases, this DMA length may exceed the info->dest_buf length and cause the above BUG condition. Fix it by capping the copy length to not exceed the length of info->dest_buf. The extra DMA data contains no useful information. This code path is shared for the HWRM_DBG_COREDUMP_LIST and the HWRM_DBG_COREDUMP_RETRIEVE FW commands. The buffering is different for these 2 FW commands. To simplify the logic, we need to move the line to adjust the buffer length for HWRM_DBG_COREDUMP_RETRIEVE up, so that the new check to cap the copy length will work for both commands.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: altmodes/displayport: do not index invalid pin_assignments A poorly implemented DisplayPort Alt Mode port partner can indicate that its pin assignment capabilities are greater than the maximum value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show will cause a BRK exception due to an out of bounds array access. Prevent for loop in pin_assignment_show from accessing invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop condition.

An out-of-bounds heap buffer access issue was found in the ARM Generic Interrupt Controller emulator of QEMU up to and including qemu 4.2.0on aarch64 platform. The issue occurs because while writing an interrupt ID to the controller memory area, it is not masked to be 4 bits wide. It may lead to the said issue while updating controller state fields and their subsequent processing. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

In the Linux kernel, the following vulnerability has been resolved: mtd: nand: ecc-mxic: Fix use of uninitialized variable ret If ctx->steps is zero, the loop processing ECC steps is skipped, and the variable ret remains uninitialized. It is later checked and returned, which leads to undefined behavior and may cause unpredictable results in user space or kernel crashes. This scenario can be triggered in edge cases such as misconfigured geometry, ECC engine misuse, or if ctx->steps is not validated after initialization. Initialize ret to zero before the loop to ensure correct and safe behavior regardless of the ctx->steps value. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: net_sched: skbprio: Remove overly strict queue assertions In the current implementation, skbprio enqueue/dequeue contains an assertion that fails under certain conditions when SKBPRIO is used as a child qdisc under TBF with specific parameters. The failure occurs because TBF sometimes peeks at packets in the child qdisc without actually dequeuing them when tokens are unavailable. This peek operation creates a discrepancy between the parent and child qdisc queue length counters. When TBF later receives a high-priority packet, SKBPRIO's queue length may show a different value than what's reflected in its internal priority queue tracking, triggering the assertion. The fix removes this overly strict assertions in SKBPRIO, they are not necessary at all.

In the Linux kernel, the following vulnerability has been resolved: crypto: marvell/cesa - Handle zero-length skcipher requests Do not access random memory for zero-length skcipher requests. Just return 0.

In the Linux kernel, the following vulnerability has been resolved: atm: Revert atm_account_tx() if copy_from_iter_full() fails. In vcc_sendmsg(), we account skb->truesize to sk->sk_wmem_alloc by atm_account_tx(). It is expected to be reverted by atm_pop_raw() later called by vcc->dev->ops->send(vcc, skb). However, vcc_sendmsg() misses the same revert when copy_from_iter_full() fails, and then we will leak a socket. Let's factorise the revert part as atm_return_tx() and call it in the failure path. Note that the corresponding sk_wmem_alloc operation can be found in alloc_tx() as of the blamed commit. $ git blame -L:alloc_tx net/atm/common.c c55fa3cccbc2c~

In the Linux kernel, the following vulnerability has been resolved: atm: clip: prevent NULL deref in clip_push() Blamed commit missed that vcc_destroy_socket() calls clip_push() with a NULL skb. If clip_devs is NULL, clip_push() then crashes when reading skb->truesize.

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Do not double dequeue a configuration request Some of our devices crash in tb_cfg_request_dequeue(): general protection fault, probably for non-canonical address 0xdead000000000122 CPU: 6 PID: 91007 Comm: kworker/6:2 Tainted: G U W 6.6.65 RIP: 0010:tb_cfg_request_dequeue+0x2d/0xa0 Call Trace: <TASK> ? tb_cfg_request_dequeue+0x2d/0xa0 tb_cfg_request_work+0x33/0x80 worker_thread+0x386/0x8f0 kthread+0xed/0x110 ret_from_fork+0x38/0x50 ret_from_fork_asm+0x1b/0x30 The circumstances are unclear, however, the theory is that tb_cfg_request_work() can be scheduled twice for a request: first time via frame.callback from ring_work() and second time from tb_cfg_request(). Both times kworkers will execute tb_cfg_request_dequeue(), which results in double list_del() from the ctl->request_queue (the list poison deference hints at it: 0xdead000000000122). Do not dequeue requests that don't have TB_CFG_REQUEST_ACTIVE bit set.

In the Linux kernel, the following vulnerability has been resolved: soc: aspeed: lpc-snoop: Don't disable channels that aren't enabled Mitigate e.g. the following: # echo 1e789080.lpc-snoop > /sys/bus/platform/drivers/aspeed-lpc-snoop/unbind ... [ 120.363594] Unable to handle kernel NULL pointer dereference at virtual address 00000004 when write [ 120.373866] [00000004] *pgd=00000000 [ 120.377910] Internal error: Oops: 805 [#1] SMP ARM [ 120.383306] CPU: 1 UID: 0 PID: 315 Comm: sh Not tainted 6.15.0-rc1-00009-g926217bc7d7d-dirty #20 NONE ... [ 120.679543] Call trace: [ 120.679559] misc_deregister from aspeed_lpc_snoop_remove+0x84/0xac [ 120.692462] aspeed_lpc_snoop_remove from platform_remove+0x28/0x38 [ 120.700996] platform_remove from device_release_driver_internal+0x188/0x200 ...

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_reject: don't leak dst refcount for loopback packets recent patches to add a WARN() when replacing skb dst entry found an old bug: WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] .. This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage. Instead of checking hook just check if the skb already has a route attached to it.

In the Linux kernel, the following vulnerability has been resolved: media: dvb-frontends: w7090p: fix null-ptr-deref in w7090p_tuner_write_serpar and w7090p_tuner_read_serpar In w7090p_tuner_write_serpar, msg is controlled by user. When msg[0].buf is null and msg[0].len is zero, former checks on msg[0].buf would be passed. If accessing msg[0].buf[2] without sanity check, null pointer deref would happen. We add check on msg[0].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

The pnv_lpc_do_eccb function in hw/ppc/pnv_lpc.c in Qemu before 3.1 allows out-of-bounds write or read access to PowerNV memory.

In the Linux kernel, the following vulnerability has been resolved: ACPICA: Refuse to evaluate a method if arguments are missing As reported in [1], a platform firmware update that increased the number of method parameters and forgot to update a least one of its callers, caused ACPICA to crash due to use-after-free. Since this a result of a clear AML issue that arguably cannot be fixed up by the interpreter (it cannot produce missing data out of thin air), address it by making ACPICA refuse to evaluate a method if the caller attempts to pass fewer arguments than expected to it.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix iteration of extrefs during log replay At __inode_add_ref() when processing extrefs, if we jump into the next label we have an undefined value of victim_name.len, since we haven't initialized it before we did the goto. This results in an invalid memory access in the next iteration of the loop since victim_name.len was not initialized to the length of the name of the current extref. Fix this by initializing victim_name.len with the current extref's name length.

In the Linux kernel, the following vulnerability has been resolved: smb/server: avoid deadlock when linking with ReplaceIfExists If smb2_create_link() is called with ReplaceIfExists set and the name does exist then a deadlock will happen. ksmbd_vfs_kern_path_locked() will return with success and the parent directory will be locked. ksmbd_vfs_remove_file() will then remove the file. ksmbd_vfs_link() will then be called while the parent is still locked. It will try to lock the same parent and will deadlock. This patch moves the ksmbd_vfs_kern_path_unlock() call to *before* ksmbd_vfs_link() and then simplifies the code, removing the file_present flag variable.

In the Linux kernel, the following vulnerability has been resolved: wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev() There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For example, the following is possible: T0 T1 zd_mac_tx_to_dev() /* len == skb_queue_len(q) */ while (len > ZD_MAC_MAX_ACK_WAITERS) { filter_ack() spin_lock_irqsave(&q->lock, flags); /* position == skb_queue_len(q) */ for (i=1; i<position; i++) skb = __skb_dequeue(q) if (mac->type == NL80211_IFTYPE_AP) skb = __skb_dequeue(q); spin_unlock_irqrestore(&q->lock, flags); skb_dequeue() -> NULL Since there is a small gap between checking skb queue length and skb being unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL. Then the pointer is passed to zd_mac_tx_status() where it is dereferenced. In order to avoid potential NULL pointer dereference due to situations like above, check if skb is not NULL before passing it to zd_mac_tx_status(). Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. When generating the MSR_IA32_PEBS_ENABLE value that will be loaded on VM-Entry to a KVM guest, mask the value with the vCPU's desired PEBS_ENABLE value. Consulting only the host kernel's host vs. guest masks results in running the guest with PEBS enabled even when the guest doesn't want to use PEBS. Because KVM uses perf events to proxy the guest virtual PMU, simply looking at exclude_host can't differentiate between events created by host userspace, and events created by KVM on behalf of the guest. Running the guest with PEBS unexpectedly enabled typically manifests as crashes due to a near-infinite stream of #PFs. E.g. if the guest hasn't written MSR_IA32_DS_AREA, the CPU will hit page faults on address '0' when trying to record PEBS events. The issue is most easily reproduced by running `perf kvm top` from before commit 7b100989b4f6 ("perf evlist: Remove __evlist__add_default") (after which, `perf kvm top` effectively stopped using PEBS). The userspace side of perf creates a guest-only PEBS event, which intel_guest_get_msrs() misconstrues a guest-*owned* PEBS event. Arguably, this is a userspace bug, as enabling PEBS on guest-only events simply cannot work, and userspace can kill VMs in many other ways (there is no danger to the host). However, even if this is considered to be bad userspace behavior, there's zero downside to perf/KVM restricting PEBS to guest-owned events. Note, commit 854250329c02 ("KVM: x86/pmu: Disable guest PEBS temporarily in two rare situations") fixed the case where host userspace is profiling KVM *and* userspace, but missed the case where userspace is profiling only KVM.

In the Linux kernel, the following vulnerability has been resolved: nfsd: decrease sc_count directly if fail to queue dl_recall A deadlock warning occurred when invoking nfs4_put_stid following a failed dl_recall queue operation: T1 T2 nfs4_laundromat nfs4_get_client_reaplist nfs4_anylock_blockers __break_lease spin_lock // ctx->flc_lock spin_lock // clp->cl_lock nfs4_lockowner_has_blockers locks_owner_has_blockers spin_lock // flctx->flc_lock nfsd_break_deleg_cb nfsd_break_one_deleg nfs4_put_stid refcount_dec_and_lock spin_lock // clp->cl_lock When a file is opened, an nfs4_delegation is allocated with sc_count initialized to 1, and the file_lease holds a reference to the delegation. The file_lease is then associated with the file through kernel_setlease. The disassociation is performed in nfsd4_delegreturn via the following call chain: nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg --> nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease The corresponding sc_count reference will be released after this disassociation. Since nfsd_break_one_deleg executes while holding the flc_lock, the disassociation process becomes blocked when attempting to acquire flc_lock in generic_delete_lease. This means: 1) sc_count in nfsd_break_one_deleg will not be decremented to 0; 2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to acquire cl_lock; 3) Consequently, no deadlock condition is created. Given that sc_count in nfsd_break_one_deleg remains non-zero, we can safely perform refcount_dec on sc_count directly. This approach effectively avoids triggering deadlock warnings.

In the Linux kernel, the following vulnerability has been resolved: net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtree htb_lookup_leaf has a BUG_ON that can trigger with the following: tc qdisc del dev lo root tc qdisc add dev lo root handle 1: htb default 1 tc class add dev lo parent 1: classid 1:1 htb rate 64bit tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2:1 handle 3: blackhole ping -I lo -c1 -W0.001 127.0.0.1 The root cause is the following: 1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on the selected leaf qdisc 2. netem_dequeue calls enqueue on the child qdisc 3. blackhole_enqueue drops the packet and returns a value that is not just NET_XMIT_SUCCESS 4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate -> htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase 5. As this is the only class in the selected hprio rbtree, __rb_change_child in __rb_erase_augmented sets the rb_root pointer to NULL 6. Because blackhole_dequeue returns NULL, netem_dequeue returns NULL, which causes htb_dequeue_tree to call htb_lookup_leaf with the same hprio rbtree, and fail the BUG_ON The function graph for this scenario is shown here: 0) | htb_enqueue() { 0) + 13.635 us | netem_enqueue(); 0) 4.719 us | htb_activate_prios(); 0) # 2249.199 us | } 0) | htb_dequeue() { 0) 2.355 us | htb_lookup_leaf(); 0) | netem_dequeue() { 0) + 11.061 us | blackhole_enqueue(); 0) | qdisc_tree_reduce_backlog() { 0) | qdisc_lookup_rcu() { 0) 1.873 us | qdisc_match_from_root(); 0) 6.292 us | } 0) 1.894 us | htb_search(); 0) | htb_qlen_notify() { 0) 2.655 us | htb_deactivate_prios(); 0) 6.933 us | } 0) + 25.227 us | } 0) 1.983 us | blackhole_dequeue(); 0) + 86.553 us | } 0) # 2932.761 us | qdisc_warn_nonwc(); 0) | htb_lookup_leaf() { 0) | BUG_ON(); ------------------------------------------ The full original bug report can be seen here [1]. We can fix this just by returning NULL instead of the BUG_ON, as htb_dequeue_tree returns NULL when htb_lookup_leaf returns NULL. [1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on sbi->total_valid_block_count syzbot reported a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/f2fs.h:2521! RIP: 0010:dec_valid_block_count+0x3b2/0x3c0 fs/f2fs/f2fs.h:2521 Call Trace: f2fs_truncate_data_blocks_range+0xc8c/0x11a0 fs/f2fs/file.c:695 truncate_dnode+0x417/0x740 fs/f2fs/node.c:973 truncate_nodes+0x3ec/0xf50 fs/f2fs/node.c:1014 f2fs_truncate_inode_blocks+0x8e3/0x1370 fs/f2fs/node.c:1197 f2fs_do_truncate_blocks+0x840/0x12b0 fs/f2fs/file.c:810 f2fs_truncate_blocks+0x10d/0x300 fs/f2fs/file.c:838 f2fs_truncate+0x417/0x720 fs/f2fs/file.c:888 f2fs_setattr+0xc4f/0x12f0 fs/f2fs/file.c:1112 notify_change+0xbca/0xe90 fs/attr.c:552 do_truncate+0x222/0x310 fs/open.c:65 handle_truncate fs/namei.c:3466 [inline] do_open fs/namei.c:3849 [inline] path_openat+0x2e4f/0x35d0 fs/namei.c:4004 do_filp_open+0x284/0x4e0 fs/namei.c:4031 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_creat fs/open.c:1522 [inline] __se_sys_creat fs/open.c:1516 [inline] __x64_sys_creat+0x124/0x170 fs/open.c:1516 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 The reason is: in fuzzed image, sbi->total_valid_block_count is inconsistent w/ mapped blocks indexed by inode, so, we should not trigger panic for such case, instead, let's print log and set fsck flag.

In the Linux kernel, the following vulnerability has been resolved: nfsd: nfsd4_spo_must_allow() must check this is a v4 compound request If the request being processed is not a v4 compound request, then examining the cstate can have undefined results. This patch adds a check that the rpc procedure being executed (rq_procinfo) is the NFSPROC4_COMPOUND procedure.

kernel/sched/fair.c in the Linux kernel before 5.3.9, when cpu.cfs_quota_us is used (e.g., with Kubernetes), allows attackers to cause a denial of service against non-cpu-bound applications by generating a workload that triggers unwanted slice expiration, aka CID-de53fd7aedb1. (In other words, although this slice expiration would typically be seen with benign workloads, it is possible that an attacker could calculate how many stray requests are required to force an entire Kubernetes cluster into a low-performance state caused by slice expiration, and ensure that a DDoS attack sent that number of stray requests. An attack does not affect the stability of the kernel; it only causes mismanagement of application execution.)

In the Linux kernel, the following vulnerability has been resolved: calipso: Fix null-ptr-deref in calipso_req_{set,del}attr(). syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344ddbe8 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netf ---truncated---

In the Linux kernel, the following vulnerability has been resolved: atm: atmtcp: Free invalid length skb in atmtcp_c_send(). syzbot reported the splat below. [0] vcc_sendmsg() copies data passed from userspace to skb and passes it to vcc->dev->ops->send(). atmtcp_c_send() accesses skb->data as struct atmtcp_hdr after checking if skb->len is 0, but it's not enough. Also, when skb->len == 0, skb and sk (vcc) were leaked because dev_kfree_skb() is not called and sk_wmem_alloc adjustment is missing to revert atm_account_tx() in vcc_sendmsg(), which is expected to be done in atm_pop_raw(). Let's properly free skb with an invalid length in atmtcp_c_send(). [0]: BUG: KMSAN: uninit-value in atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 atmtcp_c_send+0x255/0xed0 drivers/atm/atmtcp.c:294 vcc_sendmsg+0xd7c/0xff0 net/atm/common.c:644 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] vcc_sendmsg+0xb40/0xff0 net/atm/common.c:628 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2655 x64_sys_call+0x32fb/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 5798 Comm: syz-executor192 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Check device memory pointer before usage Add a NULL check before accessing device memory to prevent a crash if dev->dm allocation in mlx5_init_once() fails.

In the Linux kernel, the following vulnerability has been resolved: wifi: carl9170: do not ping device which has failed to load firmware Syzkaller reports [1, 2] crashes caused by an attempts to ping the device which has failed to load firmware. Since such a device doesn't pass 'ieee80211_register_hw()', an internal workqueue managed by 'ieee80211_queue_work()' is not yet created and an attempt to queue work on it causes null-ptr-deref. [1] https://syzkaller.appspot.com/bug?extid=9a4aec827829942045ff [2] https://syzkaller.appspot.com/bug?extid=0d8afba53e8fb2633217

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_nfacct: don't assume acct name is null-terminated BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721 Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851 [..] string+0x231/0x2b0 lib/vsprintf.c:721 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874 [..] nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523 nfnl_acct_find_get() handles non-null input, but the error printk relied on its presence.

In the Linux kernel, the following vulnerability has been resolved: ptp: remove ptp->n_vclocks check logic in ptp_vclock_in_use() There is no disagreement that we should check both ptp->is_virtual_clock and ptp->n_vclocks to check if the ptp virtual clock is in use. However, when we acquire ptp->n_vclocks_mux to read ptp->n_vclocks in ptp_vclock_in_use(), we observe a recursive lock in the call trace starting from n_vclocks_store(). ============================================ WARNING: possible recursive locking detected 6.15.0-rc6 #1 Not tainted -------------------------------------------- syz.0.1540/13807 is trying to acquire lock: ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_vclock_in_use drivers/ptp/ptp_private.h:103 [inline] ffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: ptp_clock_unregister+0x21/0x250 drivers/ptp/ptp_clock.c:415 but task is already holding lock: ffff888030704868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at: n_vclocks_store+0xf1/0x6d0 drivers/ptp/ptp_sysfs.c:215 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ptp->n_vclocks_mux); lock(&ptp->n_vclocks_mux); *** DEADLOCK *** .... ============================================ The best way to solve this is to remove the logic that checks ptp->n_vclocks in ptp_vclock_in_use(). The reason why this is appropriate is that any path that uses ptp->n_vclocks must unconditionally check if ptp->n_vclocks is greater than 0 before unregistering vclocks, and all functions are already written this way. And in the function that uses ptp->n_vclocks, we already get ptp->n_vclocks_mux before unregistering vclocks. Therefore, we need to remove the redundant check for ptp->n_vclocks in ptp_vclock_in_use() to prevent recursive locking.

In the Linux kernel, the following vulnerability has been resolved: kasan: remove kasan_find_vm_area() to prevent possible deadlock find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area().

In the Linux kernel, the following vulnerability has been resolved: nfsd: Initialize ssc before laundromat_work to prevent NULL dereference In nfs4_state_start_net(), laundromat_work may access nfsd_ssc through nfs4_laundromat -> nfsd4_ssc_expire_umount. If nfsd_ssc isn't initialized, this can cause NULL pointer dereference. Normally the delayed start of laundromat_work allows sufficient time for nfsd_ssc initialization to complete. However, when the kernel waits too long for userspace responses (e.g. in nfs4_state_start_net -> nfsd4_end_grace -> nfsd4_record_grace_done -> nfsd4_cld_grace_done -> cld_pipe_upcall -> __cld_pipe_upcall -> wait_for_completion path), the delayed work may start before nfsd_ssc initialization finishes. Fix this by moving nfsd_ssc initialization before starting laundromat_work.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix NULL pointer deference on eir_get_service_data The len parameter is considered optional so it can be NULL so it cannot be used for skipping to next entry of EIR_SERVICE_DATA.

In the Linux kernel, the following vulnerability has been resolved: comedi: Fix initialization of data for instructions that write to subdevice Some Comedi subdevice instruction handlers are known to access instruction data elements beyond the first `insn->n` elements in some cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions allocate at least `MIN_SAMPLES` (16) data elements to deal with this, but they do not initialize all of that. For Comedi instruction codes that write to the subdevice, the first `insn->n` data elements are copied from user-space, but the remaining elements are left uninitialized. That could be a problem if the subdevice instruction handler reads the uninitialized data. Ensure that the first `MIN_SAMPLES` elements are initialized before calling these instruction handlers, filling the uncopied elements with 0. For `do_insnlist_ioctl()`, the same data buffer elements are used for handling a list of instructions, so ensure the first `MIN_SAMPLES` elements are initialized for each instruction that writes to the subdevice.

In the Linux kernel, the following vulnerability has been resolved: drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling If there's support for another console device (such as a TTY serial), the kernel occasionally panics during boot. The panic message and a relevant snippet of the call stack is as follows: Unable to handle kernel NULL pointer dereference at virtual address 000000000000000 Call trace: drm_crtc_handle_vblank+0x10/0x30 (P) decon_irq_handler+0x88/0xb4 [...] Otherwise, the panics don't happen. This indicates that it's some sort of race condition. Add a check to validate if the drm device can handle vblanks before calling drm_crtc_handle_vblank() to avoid this.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Prevent division by zero The user can set any speed value. If speed is greater than UINT_MAX/8, division by zero is possible. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject invalid file types when reading inodes To prevent inodes with invalid file types from tripping through the vfs and causing malfunctions or assertion failures, add a missing sanity check when reading an inode from a block device. If the file type is not valid, treat it as a filesystem error.

In the Linux kernel, the following vulnerability has been resolved: comedi: Fail COMEDI_INSNLIST ioctl if n_insns is too large The handling of the `COMEDI_INSNLIST` ioctl allocates a kernel buffer to hold the array of `struct comedi_insn`, getting the length from the `n_insns` member of the `struct comedi_insnlist` supplied by the user. The allocation will fail with a WARNING and a stack dump if it is too large. Avoid that by failing with an `-EINVAL` error if the supplied `n_insns` value is unreasonable. Define the limit on the `n_insns` value in the `MAX_INSNS` macro. Set this to the same value as `MAX_SAMPLES` (65536), which is the maximum allowed sum of the values of the member `n` in the array of `struct comedi_insn`, and sensible comedi instructions will have an `n` of at least 1.

lintian 1.23 and earlier removes the working directory even if it was not created by lintian, which may allow local users to delete arbitrary files or directories via a symlink attack.

In the Linux kernel, the following vulnerability has been resolved: net: tls: explicitly disallow disconnect syzbot discovered that it can disconnect a TLS socket and then run into all sort of unexpected corner cases. I have a vague recollection of Eric pointing this out to us a long time ago. Supporting disconnect is really hard, for one thing if offload is enabled we'd need to wait for all packets to be _acked_. Disconnect is not commonly used, disallow it. The immediate problem syzbot run into is the warning in the strp, but that's just the easiest bug to trigger: WARNING: CPU: 0 PID: 5834 at net/tls/tls_strp.c:486 tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 RIP: 0010:tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 Call Trace: <TASK> tls_rx_rec_wait+0x280/0xa60 net/tls/tls_sw.c:1363 tls_sw_recvmsg+0x85c/0x1c30 net/tls/tls_sw.c:2043 inet6_recvmsg+0x2c9/0x730 net/ipv6/af_inet6.c:678 sock_recvmsg_nosec net/socket.c:1023 [inline] sock_recvmsg+0x109/0x280 net/socket.c:1045 __sys_recvfrom+0x202/0x380 net/socket.c:2237

In the Linux kernel, the following vulnerability has been resolved: atm: clip: Fix potential null-ptr-deref in to_atmarpd(). atmarpd is protected by RTNL since commit f3a0592b37b8 ("[ATM]: clip causes unregister hang"). However, it is not enough because to_atmarpd() is called without RTNL, especially clip_neigh_solicit() / neigh_ops->solicit() is unsleepable. Also, there is no RTNL dependency around atmarpd. Let's use a private mutex and RCU to protect access to atmarpd in to_atmarpd().