In the Linux kernel, the following vulnerability has been resolved: bonding: Fix unnecessary warnings and logs from bond_xdp_get_xmit_slave() syzbot reported a WARNING in bond_xdp_get_xmit_slave. To reproduce this[1], one bond device (bond1) has xdpdrv, which increases bpf_master_redirect_enabled_key. Another bond device (bond0) which is unsupported by XDP but its slave (veth3) has xdpgeneric that returns XDP_TX. This triggers WARN_ON_ONCE() from the xdp_master_redirect(). To reduce unnecessary warnings and improve log management, we need to delete the WARN_ON_ONCE() and add ratelimit to the netdev_err(). [1] Steps to reproduce: # Needs tx_xdp with return XDP_TX; ip l add veth0 type veth peer veth1 ip l add veth3 type veth peer veth4 ip l add bond0 type bond mode 6 # BOND_MODE_ALB, unsupported by XDP ip l add bond1 type bond # BOND_MODE_ROUNDROBIN by default ip l set veth0 master bond1 ip l set bond1 up # Increases bpf_master_redirect_enabled_key ip l set dev bond1 xdpdrv object tx_xdp.o section xdp_tx ip l set veth3 master bond0 ip l set bond0 up ip l set veth4 up # Triggers WARN_ON_ONCE() from the xdp_master_redirect() ip l set veth3 xdpgeneric object tx_xdp.o section xdp_tx

In the Linux kernel, the following vulnerability has been resolved: drivers/perf: Fix ali_drw_pmu driver interrupt status clearing The alibaba_uncore_pmu driver forgot to clear all interrupt status in the interrupt processing function. After the PMU counter overflow interrupt occurred, an interrupt storm occurred, causing the system to hang. Therefore, clear the correct interrupt status in the interrupt handling function to fix it.

In the Linux kernel, the following vulnerability has been resolved: crypto: hisilicon/qm - inject error before stopping queue The master ooo cannot be completely closed when the accelerator core reports memory error. Therefore, the driver needs to inject the qm error to close the master ooo. Currently, the qm error is injected after stopping queue, memory may be released immediately after stopping queue, causing the device to access the released memory. Therefore, error is injected to close master ooo before stopping queue to ensure that the device does not access the released memory.

In the Linux kernel, the following vulnerability has been resolved: bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input arguments, zero the value for the case of an error as otherwise it could leak memory. For tracing, it is not needed given CAP_PERFMON can already read all kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped in here. Also, the MTU helpers mtu_len pointer value is being written but also read. Technically, the MEM_UNINIT should not be there in order to always force init. Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now implies two things actually: i) write into memory, ii) memory does not have to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory, ii) memory must be initialized. This means that for bpf_*_check_mtu() we're readding the issue we're trying to fix, that is, it would then be able to write back into things like .rodata BPF maps. Follow-up work will rework the MEM_UNINIT semantics such that the intent can be better expressed. For now just clear the *mtu_len on error path which can be lifted later again.

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix "in-kernel MMIO" check TDX only supports kernel-initiated MMIO operations. The handle_mmio() function checks if the #VE exception occurred in the kernel and rejects the operation if it did not. However, userspace can deceive the kernel into performing MMIO on its behalf. For example, if userspace can point a syscall to an MMIO address, syscall does get_user() or put_user() on it, triggering MMIO #VE. The kernel will treat the #VE as in-kernel MMIO. Ensure that the target MMIO address is within the kernel before decoding instruction.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to wait dio completion It should wait all existing dio write IOs before block removal, otherwise, previous direct write IO may overwrite data in the block which may be reused by other inode.

In the Linux kernel, the following vulnerability has been resolved: jfs: fix out-of-bounds in dbNextAG() and diAlloc() In dbNextAG() , there is no check for the case where bmp->db_numag is greater or same than MAXAG due to a polluted image, which causes an out-of-bounds. Therefore, a bounds check should be added in dbMount(). And in dbNextAG(), a check for the case where agpref is greater than bmp->db_numag should be added, so an out-of-bounds exception should be prevented. Additionally, a check for the case where agno is greater or same than MAXAG should be added in diAlloc() to prevent out-of-bounds.

In the Linux kernel, the following vulnerability has been resolved: ntb: intel: Fix the NULL vs IS_ERR() bug for debugfs_create_dir() The debugfs_create_dir() function returns error pointers. It never returns NULL. So use IS_ERR() to check it.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check for set_output_gamma in dcn30_set_output_transfer_func This commit adds a null check for the set_output_gamma function pointer in the dcn30_set_output_transfer_func function. Previously, set_output_gamma was being checked for nullity at line 386, but then it was being dereferenced without any nullity check at line 401. This could potentially lead to a null pointer dereference error if set_output_gamma is indeed null. To fix this, we now ensure that set_output_gamma is not null before dereferencing it. We do this by adding a nullity check for set_output_gamma before the call to set_output_gamma at line 401. If set_output_gamma is null, we log an error message and do not call the function. This fix prevents a potential null pointer dereference error. drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:401 dcn30_set_output_transfer_func() error: we previously assumed 'mpc->funcs->set_output_gamma' could be null (see line 386) drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c 373 bool dcn30_set_output_transfer_func(struct dc *dc, 374 struct pipe_ctx *pipe_ctx, 375 const struct dc_stream_state *stream) 376 { 377 int mpcc_id = pipe_ctx->plane_res.hubp->inst; 378 struct mpc *mpc = pipe_ctx->stream_res.opp->ctx->dc->res_pool->mpc; 379 const struct pwl_params *params = NULL; 380 bool ret = false; 381 382 /* program OGAM or 3DLUT only for the top pipe*/ 383 if (pipe_ctx->top_pipe == NULL) { 384 /*program rmu shaper and 3dlut in MPC*/ 385 ret = dcn30_set_mpc_shaper_3dlut(pipe_ctx, stream); 386 if (ret == false && mpc->funcs->set_output_gamma) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If this is NULL 387 if (stream->out_transfer_func.type == TF_TYPE_HWPWL) 388 params = &stream->out_transfer_func.pwl; 389 else if (pipe_ctx->stream->out_transfer_func.type == 390 TF_TYPE_DISTRIBUTED_POINTS && 391 cm3_helper_translate_curve_to_hw_format( 392 &stream->out_transfer_func, 393 &mpc->blender_params, false)) 394 params = &mpc->blender_params; 395 /* there are no ROM LUTs in OUTGAM */ 396 if (stream->out_transfer_func.type == TF_TYPE_PREDEFINED) 397 BREAK_TO_DEBUGGER(); 398 } 399 } 400 --> 401 mpc->funcs->set_output_gamma(mpc, mpcc_id, params); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Then it will crash 402 return ret; 403 }

In the Linux kernel, the following vulnerability has been resolved: iommufd: Protect against overflow of ALIGN() during iova allocation Userspace can supply an iova and uptr such that the target iova alignment becomes really big and ALIGN() overflows which corrupts the selected area range during allocation. CONFIG_IOMMUFD_TEST can detect this: WARNING: CPU: 1 PID: 5092 at drivers/iommu/iommufd/io_pagetable.c:268 iopt_alloc_area_pages drivers/iommu/iommufd/io_pagetable.c:268 [inline] WARNING: CPU: 1 PID: 5092 at drivers/iommu/iommufd/io_pagetable.c:268 iopt_map_pages+0xf95/0x1050 drivers/iommu/iommufd/io_pagetable.c:352 Modules linked in: CPU: 1 PID: 5092 Comm: syz-executor294 Not tainted 6.10.0-rc5-syzkaller-00294-g3ffea9a7a6f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:iopt_alloc_area_pages drivers/iommu/iommufd/io_pagetable.c:268 [inline] RIP: 0010:iopt_map_pages+0xf95/0x1050 drivers/iommu/iommufd/io_pagetable.c:352 Code: fc e9 a4 f3 ff ff e8 1a 8b 4c fc 41 be e4 ff ff ff e9 8a f3 ff ff e8 0a 8b 4c fc 90 0f 0b 90 e9 37 f5 ff ff e8 fc 8a 4c fc 90 <0f> 0b 90 e9 68 f3 ff ff 48 c7 c1 ec 82 ad 8f 80 e1 07 80 c1 03 38 RSP: 0018:ffffc90003ebf9e0 EFLAGS: 00010293 RAX: ffffffff85499fa4 RBX: 00000000ffffffef RCX: ffff888079b49e00 RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 0000000000000000 RBP: ffffc90003ebfc50 R08: ffffffff85499b30 R09: ffffffff85499942 R10: 0000000000000002 R11: ffff888079b49e00 R12: ffff8880228e0010 R13: 0000000000000000 R14: 1ffff920007d7f68 R15: ffffc90003ebfd00 FS: 000055557d760380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005fdeb8 CR3: 000000007404a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> iommufd_ioas_copy+0x610/0x7b0 drivers/iommu/iommufd/ioas.c:274 iommufd_fops_ioctl+0x4d9/0x5a0 drivers/iommu/iommufd/main.c:421 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Cap the automatic alignment to the huge page size, which is probably a better idea overall. Huge automatic alignments can fragment and chew up the available IOVA space without any reason.

In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: always wait for both firmware loading attempts In 'rtw_wait_firmware_completion()', always wait for both (regular and wowlan) firmware loading attempts. Otherwise if 'rtw_usb_intf_init()' has failed in 'rtw_usb_probe()', 'rtw_usb_disconnect()' may issue 'ieee80211_free_hw()' when one of 'rtw_load_firmware_cb()' (usually the wowlan one) is still in progress, causing UAF detected by KASAN.

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: use hweight16 to get correct tx antenna The chainmask is u16 so using hweight8 cannot get correct tx_ant. Without this patch, the tx_ant of band 2 would be -1 and lead to the following issue: BUG: KASAN: stack-out-of-bounds in mt7996_mcu_add_sta+0x12e0/0x16e0 [mt7996e]

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop() Since '__dev_queue_xmit()' should be called with interrupts enabled, the following backtrace: ieee80211_do_stop() ... spin_lock_irqsave(&local->queue_stop_reason_lock, flags) ... ieee80211_free_txskb() ieee80211_report_used_skb() ieee80211_report_ack_skb() cfg80211_mgmt_tx_status_ext() nl80211_frame_tx_status() genlmsg_multicast_netns() genlmsg_multicast_netns_filtered() nlmsg_multicast_filtered() netlink_broadcast_filtered() do_one_broadcast() netlink_broadcast_deliver() __netlink_sendskb() netlink_deliver_tap() __netlink_deliver_tap_skb() dev_queue_xmit() __dev_queue_xmit() ; with IRQS disabled ... spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags) issues the warning (as reported by syzbot reproducer): WARNING: CPU: 2 PID: 5128 at kernel/softirq.c:362 __local_bh_enable_ip+0xc3/0x120 Fix this by implementing a two-phase skb reclamation in 'ieee80211_do_stop()', where actual work is performed outside of a section with interrupts disabled.

In the Linux kernel, the following vulnerability has been resolved: sock_map: Add a cond_resched() in sock_hash_free() Several syzbot soft lockup reports all have in common sock_hash_free() If a map with a large number of buckets is destroyed, we need to yield the cpu when needed.

In the Linux kernel, the following vulnerability has been resolved: ipv6: avoid possible NULL deref in rt6_uncached_list_flush_dev() Blamed commit accidentally removed a check for rt->rt6i_idev being NULL, as spotted by syzbot: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 10998 Comm: syz-executor Not tainted 6.11.0-rc6-syzkaller-00208-g625403177711 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:rt6_uncached_list_flush_dev net/ipv6/route.c:177 [inline] RIP: 0010:rt6_disable_ip+0x33e/0x7e0 net/ipv6/route.c:4914 Code: 41 80 3c 04 00 74 0a e8 90 d0 9b f7 48 8b 7c 24 08 48 8b 07 48 89 44 24 10 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 64 d0 9b f7 48 8b 44 24 18 49 39 06 RSP: 0018:ffffc900047374e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff1100fdf8f33 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807efc78c0 RBP: ffffc900047375d0 R08: 0000000000000003 R09: fffff520008e6e8c R10: dffffc0000000000 R11: fffff520008e6e8c R12: 1ffff1100fdf8f18 R13: ffff88807efc7998 R14: 0000000000000000 R15: ffff88807efc7930 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002a80 CR3: 0000000022f62000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> addrconf_ifdown+0x15d/0x1bd0 net/ipv6/addrconf.c:3856 addrconf_notify+0x3cb/0x1020 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline] call_netdevice_notifiers net/core/dev.c:2046 [inline] unregister_netdevice_many_notify+0xd81/0x1c40 net/core/dev.c:11352 unregister_netdevice_many net/core/dev.c:11414 [inline] unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11289 unregister_netdevice include/linux/netdevice.h:3129 [inline] __tun_detach+0x6b9/0x1600 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x108/0x1b0 drivers/net/tun.c:3510 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1acc77def9 Code: Unable to access opcode bytes at 0x7f1acc77decf. RSP: 002b:00007ffeb26fa738 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1acc77def9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007f1acc7dd508 R08: 00007ffeb26f84d7 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 00000000ffffffff R15: 00007ffeb26fa8e0 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:rt6_uncached_list_flush_dev net/ipv6/route.c:177 [inline] RIP: 0010:rt6_disable_ip+0x33e/0x7e0 net/ipv6/route.c:4914 Code: 41 80 3c 04 00 74 0a e8 90 d0 9b f7 48 8b 7c 24 08 48 8b 07 48 89 44 24 10 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 64 d0 9b f7 48 8b 44 24 18 49 39 06 RSP: 0018:ffffc900047374e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff1100fdf8f33 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807efc78c0 R ---truncated---

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix possible UAF for bfqq->bic with merge chain 1) initial state, three tasks: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | Λ | Λ | Λ | | | | | | V | V | V | bfqq1 bfqq2 bfqq3 process ref: 1 1 1 2) bfqq1 merged to bfqq2: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | | | Λ \--------------\| | | V V | bfqq1--------->bfqq2 bfqq3 process ref: 0 2 1 3) bfqq2 merged to bfqq3: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) here -> Λ | | \--------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3 process ref: 0 1 3 In this case, IO from Process 1 will get bfqq2 from BIC1 first, and then get bfqq3 through merge chain, and finially handle IO by bfqq3. Howerver, current code will think bfqq2 is owned by BIC1, like initial state, and set bfqq2->bic to BIC1. bfq_insert_request -> by Process 1 bfqq = bfq_init_rq(rq) bfqq = bfq_get_bfqq_handle_split bfqq = bic_to_bfqq -> get bfqq2 from BIC1 bfqq->ref++ rq->elv.priv[0] = bic rq->elv.priv[1] = bfqq if (bfqq_process_refs(bfqq) == 1) bfqq->bic = bic -> record BIC1 to bfqq2 __bfq_insert_request new_bfqq = bfq_setup_cooperator -> get bfqq3 from bfqq2->new_bfqq bfqq_request_freed(bfqq) new_bfqq->ref++ rq->elv.priv[1] = new_bfqq -> handle IO by bfqq3 Fix the problem by checking bfqq is from merge chain fist. And this might fix a following problem reported by our syzkaller(unreproducible): ================================================================== BUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] BUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] BUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 Write of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595 CPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Workqueue: kblockd blk_mq_requeue_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x10d/0x610 mm/kasan/report.c:475 kasan_report+0x8e/0xc0 mm/kasan/report.c:588 bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757 bfq_init_rq block/bfq-iosched.c:6876 [inline] bfq_insert_request block/bfq-iosched.c:6254 [inline] bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304 blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593 blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 </TASK> Allocated by task 20776: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3458 [inline] kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503 ioc_create_icq block/blk-ioc.c:370 [inline] ---truncated---

In the Linux kernel, the following vulnerability has been resolved: block: fix potential invalid pointer dereference in blk_add_partition The blk_add_partition() function initially used a single if-condition (IS_ERR(part)) to check for errors when adding a partition. This was modified to handle the specific case of -ENXIO separately, allowing the function to proceed without logging the error in this case. However, this change unintentionally left a path where md_autodetect_dev() could be called without confirming that part is a valid pointer. This commit separates the error handling logic by splitting the initial if-condition, improving code readability and handling specific error scenarios explicitly. The function now distinguishes the general error case from -ENXIO without altering the existing behavior of md_autodetect_dev() calls.

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: bpf, lsm: Add check for BPF LSM return value A bpf prog returning a positive number attached to file_alloc_security hook makes kernel panic. This happens because file system can not filter out the positive number returned by the LSM prog using IS_ERR, and misinterprets this positive number as a file pointer. Given that hook file_alloc_security never returned positive number before the introduction of BPF LSM, and other BPF LSM hooks may encounter similar issues, this patch adds LSM return value check in verifier, to ensure no unexpected value is returned.

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid OOB when system.data xattr changes underneath the filesystem When looking up for an entry in an inlined directory, if e_value_offs is changed underneath the filesystem by some change in the block device, it will lead to an out-of-bounds access that KASAN detects as an UAF. EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. loop0: detected capacity change from 2048 to 2047 ================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 Read of size 1 at addr ffff88803e91130f by task syz-executor269/5103 CPU: 0 UID: 0 PID: 5103 Comm: syz-executor269 Not tainted 6.11.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 ext4_find_inline_entry+0x4be/0x5e0 fs/ext4/inline.c:1697 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1573 ext4_lookup_entry fs/ext4/namei.c:1727 [inline] ext4_lookup+0x15f/0x750 fs/ext4/namei.c:1795 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633 filename_create+0x297/0x540 fs/namei.c:3980 do_symlinkat+0xf9/0x3a0 fs/namei.c:4587 __do_sys_symlinkat fs/namei.c:4610 [inline] __se_sys_symlinkat fs/namei.c:4607 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3e73ced469 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff4d40c258 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007f3e73ced469 RDX: 0000000020000200 RSI: 00000000ffffff9c RDI: 00000000200001c0 RBP: 0000000000000000 R08: 00007fff4d40c290 R09: 00007fff4d40c290 R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 00007fff4d40c27c R13: 0000000000000003 R14: 431bde82d7b634db R15: 00007fff4d40c2b0 </TASK> Calling ext4_xattr_ibody_find right after reading the inode with ext4_get_inode_loc will lead to a check of the validity of the xattrs, avoiding this problem.