Use After Free

In the Linux kernel, the following vulnerability has been resolved: wifi: rtl8xxxu: add cancel_work_sync() for c2hcmd_work The workqueue might still be running, when the driver is stopped. To avoid a use-after-free, call cancel_work_sync() in rtl8xxxu_stop().Show less

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7925e: fix use-after-free in free_irq() From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test to make sure the shared irq handler should be able to handle the unexpected event after deregistration. For this case, let's apply MT76_REMOVED flag to indicate the device was removed and do not run into the resource access anymore.Show less

In the Linux kernel, the following vulnerability has been resolved: media: edia: dvbdev: fix a use-after-free In dvb_register_device, *pdvbdev is set equal to dvbdev, which is freed in several error-handling paths. However, *pdvbdev is not set to NULL after dvbdev's deallocation, causing use-after-frees in many places, for example, in the following call chain: budget_register |-> dvb_dmxdev_init |-> dvb_register_device |-> dvb_dmxdev_release |-> dvb_unregister_device |-> dvb_remove_device |-> dvb_device_put |-> kref_put When calling dvb_unregister_device, dmxdev->dvbdev (i.e. *pdvbdev in dvb_register_device) could point to memory that had been freed in dvb_register_device. Thereafter, this pointer is transferred to kref_put and triggering a use-after-free.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error When ncm function is working and then stop usb0 interface for link down, eth_stop() is called. At this piont, accidentally if usb transport error should happen in usb_ep_enable(), 'in_ep' and/or 'out_ep' may not be enabled. After that, ncm_disable() is called to disable for ncm unbind but gether_disconnect() is never called since 'in_ep' is not enabled. As the result, ncm object is released in ncm unbind but 'dev->port_usb' associated to 'ncm->port' is not NULL. And when ncm bind again to recover netdev, ncm object is reallocated but usb0 interface is already associated to previous released ncm object. Therefore, once usb0 interface is up and eth_start_xmit() is called, released ncm object is dereferrenced and it might cause use-after-free memory. [function unlink via configfs] usb0: eth_stop dev->port_usb=ffffff9b179c3200 --> error happens in usb_ep_enable(). NCM: ncm_disable: ncm=ffffff9b179c3200 --> no gether_disconnect() since ncm->port.in_ep->enabled is false. NCM: ncm_unbind: ncm unbind ncm=ffffff9b179c3200 NCM: ncm_free: ncm free ncm=ffffff9b179c3200 <-- released ncm [function link via configfs] NCM: ncm_alloc: ncm alloc ncm=ffffff9ac4f8a000 NCM: ncm_bind: ncm bind ncm=ffffff9ac4f8a000 NCM: ncm_set_alt: ncm=ffffff9ac4f8a000 alt=0 usb0: eth_open dev->port_usb=ffffff9b179c3200 <-- previous released ncm usb0: eth_start dev->port_usb=ffffff9b179c3200 <-- eth_start_xmit() --> dev->wrap() Unable to handle kernel paging request at virtual address dead00000000014f This patch addresses the issue by checking if 'ncm->netdev' is not NULL at ncm_disable() to call gether_disconnect() to deassociate 'dev->port_usb'. It's more reasonable to check 'ncm->netdev' to call gether_connect/disconnect rather than check 'ncm->port.in_ep->enabled' since it might not be enabled but the gether connection might be established.Show less

In the Linux kernel, the following vulnerability has been resolved: bootconfig: use memblock_free_late to free xbc memory to buddy On the time to free xbc memory in xbc_exit(), memblock may has handed over memory to buddy allocator. So it doesn't make sense to free memory back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs shows this case. This patch fixes the xbc memory free problem by calling memblock_free() in early xbc init error rewind path and calling memblock_free_late() in xbc exit path to free memory to buddy allocator. [ 9.410890] ================================================================== [ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260 [ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1 [ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5 [ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023 [ 9.460789] Call Trace: [ 9.463518] <TASK> [ 9.465859] dump_stack_lvl+0x53/0x70 [ 9.469949] print_report+0xce/0x610 [ 9.473944] ? __virt_addr_valid+0xf5/0x1b0 [ 9.478619] ? memblock_isolate_range+0x12d/0x260 [ 9.483877] kasan_report+0xc6/0x100 [ 9.487870] ? memblock_isolate_range+0x12d/0x260 [ 9.493125] memblock_isolate_range+0x12d/0x260 [ 9.498187] memblock_phys_free+0xb4/0x160 [ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10 [ 9.508021] ? mutex_unlock+0x7e/0xd0 [ 9.512111] ? __pfx_mutex_unlock+0x10/0x10 [ 9.516786] ? kernel_init_freeable+0x2d4/0x430 [ 9.521850] ? __pfx_kernel_init+0x10/0x10 [ 9.526426] xbc_exit+0x17/0x70 [ 9.529935] kernel_init+0x38/0x1e0 [ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30 [ 9.538601] ret_from_fork+0x2c/0x50 [ 9.542596] ? __pfx_kernel_init+0x10/0x10 [ 9.547170] ret_from_fork_asm+0x1a/0x30 [ 9.551552] </TASK> [ 9.555649] The buggy address belongs to the physical page: [ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30 [ 9.570821] flags: 0x200000000000000(node=0|zone=2) [ 9.576271] page_type: 0xffffffff() [ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000 [ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 9.597476] page dumped because: kasan: bad access detected [ 9.605362] Memory state around the buggy address: [ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.634930] ^ [ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 9.654675] ==================================================================Show less

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - resolve race condition during AER recovery During the PCI AER system's error recovery process, the kernel driver may encounter a race condition with freeing the reset_data structure's memory. If the device restart will take more than 10 seconds the function scheduling that restart will exit due to a timeout, and the reset_data structure will be freed. However, this data structure is used for completion notification after the restart is completed, which leads to a UAF bug. This results in a KFENCE bug notice. BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat] Use-after-free read at 0x00000000bc56fddf (in kfence-#142): adf_device_reset_worker+0x38/0xa0 [intel_qat] process_one_work+0x173/0x340 To resolve this race condition, the memory associated to the container of the work_struct is freed on the worker if the timeout expired, otherwise on the function that schedules the worker. The timeout detection can be done by checking if the caller is still waiting for completion or not by using completion_done() function.Show less

In the Linux kernel, the following vulnerability has been resolved: mac802154: fix llsec key resources release in mac802154_llsec_key_del mac802154_llsec_key_del() can free resources of a key directly without following the RCU rules for waiting before the end of a grace period. This may lead to use-after-free in case llsec_lookup_key() is traversing the list of keys in parallel with a key deletion: refcount_t: addition on 0; use-after-free. WARNING: CPU: 4 PID: 16000 at lib/refcount.c:25 refcount_warn_saturate+0x162/0x2a0 Modules linked in: CPU: 4 PID: 16000 Comm: wpan-ping Not tainted 6.7.0 #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x162/0x2a0 Call Trace: <TASK> llsec_lookup_key.isra.0+0x890/0x9e0 mac802154_llsec_encrypt+0x30c/0x9c0 ieee802154_subif_start_xmit+0x24/0x1e0 dev_hard_start_xmit+0x13e/0x690 sch_direct_xmit+0x2ae/0xbc0 __dev_queue_xmit+0x11dd/0x3c20 dgram_sendmsg+0x90b/0xd60 __sys_sendto+0x466/0x4c0 __x64_sys_sendto+0xe0/0x1c0 do_syscall_64+0x45/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Also, ieee802154_llsec_key_entry structures are not freed by mac802154_llsec_key_del(): unreferenced object 0xffff8880613b6980 (size 64): comm "iwpan", pid 2176, jiffies 4294761134 (age 60.475s) hex dump (first 32 bytes): 78 0d 8f 18 80 88 ff ff 22 01 00 00 00 00 ad de x......."....... 00 00 00 00 00 00 00 00 03 00 cd ab 00 00 00 00 ................ backtrace: [<ffffffff81dcfa62>] __kmem_cache_alloc_node+0x1e2/0x2d0 [<ffffffff81c43865>] kmalloc_trace+0x25/0xc0 [<ffffffff88968b09>] mac802154_llsec_key_add+0xac9/0xcf0 [<ffffffff8896e41a>] ieee802154_add_llsec_key+0x5a/0x80 [<ffffffff8892adc6>] nl802154_add_llsec_key+0x426/0x5b0 [<ffffffff86ff293e>] genl_family_rcv_msg_doit+0x1fe/0x2f0 [<ffffffff86ff46d1>] genl_rcv_msg+0x531/0x7d0 [<ffffffff86fee7a9>] netlink_rcv_skb+0x169/0x440 [<ffffffff86ff1d88>] genl_rcv+0x28/0x40 [<ffffffff86fec15c>] netlink_unicast+0x53c/0x820 [<ffffffff86fecd8b>] netlink_sendmsg+0x93b/0xe60 [<ffffffff86b91b35>] ____sys_sendmsg+0xac5/0xca0 [<ffffffff86b9c3dd>] ___sys_sendmsg+0x11d/0x1c0 [<ffffffff86b9c65a>] __sys_sendmsg+0xfa/0x1d0 [<ffffffff88eadbf5>] do_syscall_64+0x45/0xf0 [<ffffffff890000ea>] entry_SYSCALL_64_after_hwframe+0x6e/0x76 Handle the proper resource release in the RCU callback function mac802154_llsec_key_del_rcu(). Note that if llsec_lookup_key() finds a key, it gets a refcount via llsec_key_get() and locally copies key id from key_entry (which is a list element). So it's safe to call llsec_key_put() and free the list entry after the RCU grace period elapses. Found by Linux Verification Center (linuxtesting.org).Show less

In the Linux kernel, the following vulnerability has been resolved: nfs: fix UAF in direct writes In production we have been hitting the following warning consistently ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0 Workqueue: nfsiod nfs_direct_write_schedule_work [nfs] RIP: 0010:refcount_warn_saturate+0x9c/0xe0 PKRU: 55555554 Call Trace: <TASK> ? __warn+0x9f/0x130 ? refcount_warn_saturate+0x9c/0xe0 ? report_bug+0xcc/0x150 ? handle_bug+0x3d/0x70 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0x9c/0xe0 nfs_direct_write_schedule_work+0x237/0x250 [nfs] process_one_work+0x12f/0x4a0 worker_thread+0x14e/0x3b0 ? ZSTD_getCParams_internal+0x220/0x220 kthread+0xdc/0x120 ? __btf_name_valid+0xa0/0xa0 ret_from_fork+0x1f/0x30 This is because we're completing the nfs_direct_request twice in a row. The source of this is when we have our commit requests to submit, we process them and send them off, and then in the completion path for the commit requests we have if (nfs_commit_end(cinfo.mds)) nfs_direct_write_complete(dreq); However since we're submitting asynchronous requests we sometimes have one that completes before we submit the next one, so we end up calling complete on the nfs_direct_request twice. The only other place we use nfs_generic_commit_list() is in __nfs_commit_inode, which wraps this call in a nfs_commit_begin(); nfs_commit_end(); Which is a common pattern for this style of completion handling, one that is also repeated in the direct code with get_dreq()/put_dreq() calls around where we process events as well as in the completion paths. Fix this by using the same pattern for the commit requests. Before with my 200 node rocksdb stress running this warning would pop every 10ish minutes. With my patch the stress test has been running for several hours without popping.Show less

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: fix reference counting on zcrypt card objects Tests with hot-plugging crytpo cards on KVM guests with debug kernel build revealed an use after free for the load field of the struct zcrypt_card. The reason was an incorrect reference handling of the zcrypt card object which could lead to a free of the zcrypt card object while it was still in use. This is an example of the slab message: kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43 kernel: kmalloc_trace+0x3f2/0x470 kernel: zcrypt_card_alloc+0x36/0x70 [zcrypt] kernel: zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4] kernel: ap_device_probe+0x15c/0x290 kernel: really_probe+0xd2/0x468 kernel: driver_probe_device+0x40/0xf0 kernel: __device_attach_driver+0xc0/0x140 kernel: bus_for_each_drv+0x8c/0xd0 kernel: __device_attach+0x114/0x198 kernel: bus_probe_device+0xb4/0xc8 kernel: device_add+0x4d2/0x6e0 kernel: ap_scan_adapter+0x3d0/0x7c0 kernel: ap_scan_bus+0x5a/0x3b0 kernel: ap_scan_bus_wq_callback+0x40/0x60 kernel: process_one_work+0x26e/0x620 kernel: worker_thread+0x21c/0x440 kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43 kernel: kfree+0x37e/0x418 kernel: zcrypt_card_put+0x54/0x80 [zcrypt] kernel: ap_device_remove+0x4c/0xe0 kernel: device_release_driver_internal+0x1c4/0x270 kernel: bus_remove_device+0x100/0x188 kernel: device_del+0x164/0x3c0 kernel: device_unregister+0x30/0x90 kernel: ap_scan_adapter+0xc8/0x7c0 kernel: ap_scan_bus+0x5a/0x3b0 kernel: ap_scan_bus_wq_callback+0x40/0x60 kernel: process_one_work+0x26e/0x620 kernel: worker_thread+0x21c/0x440 kernel: kthread+0x150/0x168 kernel: __ret_from_fork+0x3c/0x58 kernel: ret_from_fork+0xa/0x30 kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff) kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88 kernel: Redzone 00000000885a74b0: bb bb bb bb bb bb bb bb ........ kernel: Object 00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk kernel: Object 00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk kernel: Object 00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk kernel: Object 00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk kernel: Object 00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk kernel: Object 00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5 kkkkkkkkkkhKkkk. kernel: Redzone 00000000885a7518: bb bb bb bb bb bb bb bb ........ kernel: Padding 00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2 kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux) kernel: Call Trace: kernel: [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120 kernel: [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140 kernel: [<00000000c99d53cc>] check_object+0x334/0x3f8 kernel: [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8 kernel: [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0 kernel: [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8 kernel: [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8 kernel: [<00000000c99dc8dc>] __kmalloc+0x434/0x590 kernel: [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0 kernel: [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0 kernel: ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: wireguard: netlink: check for dangling peer via is_dead instead of empty list If all peers are removed via wg_peer_remove_all(), rather than setting peer_list to empty, the peer is added to a temporary list with a head on the stack of wg_peer_remove_all(). If a netlink dump is resumed and the cursored peer is one that has been removed via wg_peer_remove_all(), it will iterate from that peer and then attempt to dump freed peers. Fix this by instead checking peer->is_dead, which was explictly created for this purpose. Also move up the device_update_lock lockdep assertion, since reading is_dead relies on that. It can be reproduced by a small script like: echo "Setting config..." ip link add dev wg0 type wireguard wg setconf wg0 /big-config ( while true; do echo "Showing config..." wg showconf wg0 > /dev/null done ) & sleep 4 wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n") Resulting in: BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20 Read of size 8 at addr ffff88811956ec70 by task wg/59 CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5 Call Trace: <TASK> dump_stack_lvl+0x47/0x70 print_address_description.constprop.0+0x2c/0x380 print_report+0xab/0x250 kasan_report+0xba/0xf0 __lock_acquire+0x182a/0x1b20 lock_acquire+0x191/0x4b0 down_read+0x80/0x440 get_peer+0x140/0xcb0 wg_get_device_dump+0x471/0x1130Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: fix use-after-free in do_zone_finish() Shinichiro reported the following use-after-free triggered by the device replace operation in fstests btrfs/070. BTRFS info (device nullb1): scrub: finished on devid 1 with status: 0 ================================================================== BUG: KASAN: slab-use-after-free in do_zone_finish+0x91a/0xb90 [btrfs] Read of size 8 at addr ffff8881543c8060 by task btrfs-cleaner/3494007 CPU: 0 PID: 3494007 Comm: btrfs-cleaner Tainted: G W 6.8.0-rc5-kts #1 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Call Trace: <TASK> dump_stack_lvl+0x5b/0x90 print_report+0xcf/0x670 ? __virt_addr_valid+0x200/0x3e0 kasan_report+0xd8/0x110 ? do_zone_finish+0x91a/0xb90 [btrfs] ? do_zone_finish+0x91a/0xb90 [btrfs] do_zone_finish+0x91a/0xb90 [btrfs] btrfs_delete_unused_bgs+0x5e1/0x1750 [btrfs] ? __pfx_btrfs_delete_unused_bgs+0x10/0x10 [btrfs] ? btrfs_put_root+0x2d/0x220 [btrfs] ? btrfs_clean_one_deleted_snapshot+0x299/0x430 [btrfs] cleaner_kthread+0x21e/0x380 [btrfs] ? __pfx_cleaner_kthread+0x10/0x10 [btrfs] kthread+0x2e3/0x3c0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> Allocated by task 3493983: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 btrfs_alloc_device+0xb3/0x4e0 [btrfs] device_list_add.constprop.0+0x993/0x1630 [btrfs] btrfs_scan_one_device+0x219/0x3d0 [btrfs] btrfs_control_ioctl+0x26e/0x310 [btrfs] __x64_sys_ioctl+0x134/0x1b0 do_syscall_64+0x99/0x190 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Freed by task 3494056: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3f/0x60 poison_slab_object+0x102/0x170 __kasan_slab_free+0x32/0x70 kfree+0x11b/0x320 btrfs_rm_dev_replace_free_srcdev+0xca/0x280 [btrfs] btrfs_dev_replace_finishing+0xd7e/0x14f0 [btrfs] btrfs_dev_replace_by_ioctl+0x1286/0x25a0 [btrfs] btrfs_ioctl+0xb27/0x57d0 [btrfs] __x64_sys_ioctl+0x134/0x1b0 do_syscall_64+0x99/0x190 entry_SYSCALL_64_after_hwframe+0x6e/0x76 The buggy address belongs to the object at ffff8881543c8000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 96 bytes inside of freed 1024-byte region [ffff8881543c8000, ffff8881543c8400) The buggy address belongs to the physical page: page:00000000fe2c1285 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1543c8 head:00000000fe2c1285 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x17ffffc0000840(slab|head|node=0|zone=2|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 0017ffffc0000840 ffff888100042dc0 ffffea0019e8f200 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881543c7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881543c7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881543c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881543c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881543c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb This UAF happens because we're accessing stale zone information of a already removed btrfs_device in do_zone_finish(). The sequence of events is as follows: btrfs_dev_replace_start btrfs_scrub_dev btrfs_dev_replace_finishing btrfs_dev_replace_update_device_in_mapping_tree <-- devices replaced btrfs_rm_dev_replace_free_srcdev btrfs_free_device <-- device freed cleaner_kthread btrfs_delete_unused_bgs btrfs_zone_finish do_zone_finish <-- refers the freed device The reason for this is that we're using a ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: drm/i915/vma: Fix UAF on destroy against retire race Object debugging tools were sporadically reporting illegal attempts to free a still active i915 VMA object when parking a GT believed to be idle. [161.359441] ODEBUG: free active (active state 0) object: ffff88811643b958 object type: i915_active hint: __i915_vma_active+0x0/0x50 [i915] [161.360082] WARNING: CPU: 5 PID: 276 at lib/debugobjects.c:514 debug_print_object+0x80/0xb0 ... [161.360304] CPU: 5 PID: 276 Comm: kworker/5:2 Not tainted 6.5.0-rc1-CI_DRM_13375-g003f860e5577+ #1 [161.360314] Hardware name: Intel Corporation Rocket Lake Client Platform/RocketLake S UDIMM 6L RVP, BIOS RKLSFWI1.R00.3173.A03.2204210138 04/21/2022 [161.360322] Workqueue: i915-unordered __intel_wakeref_put_work [i915] [161.360592] RIP: 0010:debug_print_object+0x80/0xb0 ... [161.361347] debug_object_free+0xeb/0x110 [161.361362] i915_active_fini+0x14/0x130 [i915] [161.361866] release_references+0xfe/0x1f0 [i915] [161.362543] i915_vma_parked+0x1db/0x380 [i915] [161.363129] __gt_park+0x121/0x230 [i915] [161.363515] ____intel_wakeref_put_last+0x1f/0x70 [i915] That has been tracked down to be happening when another thread is deactivating the VMA inside __active_retire() helper, after the VMA's active counter has been already decremented to 0, but before deactivation of the VMA's object is reported to the object debugging tool. We could prevent from that race by serializing i915_active_fini() with __active_retire() via ref->tree_lock, but that wouldn't stop the VMA from being used, e.g. from __i915_vma_retire() called at the end of __active_retire(), after that VMA has been already freed by a concurrent i915_vma_destroy() on return from the i915_active_fini(). Then, we should rather fix the issue at the VMA level, not in i915_active. Since __i915_vma_parked() is called from __gt_park() on last put of the GT's wakeref, the issue could be addressed by holding the GT wakeref long enough for __active_retire() to complete before that wakeref is released and the GT parked. I believe the issue was introduced by commit d93939730347 ("drm/i915: Remove the vma refcount") which moved a call to i915_active_fini() from a dropped i915_vma_release(), called on last put of the removed VMA kref, to i915_vma_parked() processing path called on last put of a GT wakeref. However, its visibility to the object debugging tool was suppressed by a bug in i915_active that was fixed two weeks later with commit e92eb246feb9 ("drm/i915/active: Fix missing debug object activation"). A VMA associated with a request doesn't acquire a GT wakeref by itself. Instead, it depends on a wakeref held directly by the request's active intel_context for a GT associated with its VM, and indirectly on that intel_context's engine wakeref if the engine belongs to the same GT as the VMA's VM. Those wakerefs are released asynchronously to VMA deactivation. Fix the issue by getting a wakeref for the VMA's GT when activating it, and putting that wakeref only after the VMA is deactivated. However, exclude global GTT from that processing path, otherwise the GPU never goes idle. Since __i915_vma_retire() may be called from atomic contexts, use async variant of wakeref put. Also, to avoid circular locking dependency, take care of acquiring the wakeref before VM mutex when both are needed. v7: Add inline comments with justifications for: - using untracked variants of intel_gt_pm_get/put() (Nirmoy), - using async variant of _put(), - not getting the wakeref in case of a global GTT, - always getting the first wakeref outside vm->mutex. v6: Since __i915_vma_active/retire() callbacks are not serialized, storing a wakeref tracking handle inside struct i915_vma is not safe, and there is no other good place for that. Use untracked variants of intel_gt_pm_get/put_async(). v5: Replace "tile" with "GT" across commit description (Rodrigo), - ---truncated---Show less

A use-after-free vulnerability exists in the way Foxit Reader 2024.1.0.23997 handles a Barcode widget. A specially crafted JavaScript code inside a malicious PDF document can trigger reuse of a previously freed object, which can lead to memory corruption and result in arbitrary code execution. An attacker needs to trick the user into opening the malicious file to trigger this vulnerability. Exploitation is also possible if a user visits a specially crafted, malicious site if the browser plugin extension is enabled.Show less

A use-after-free vulnerability exists in the way Foxit Reader 2024.1.0.23997 handles a ComboBox widget. A specially crafted JavaScript code inside a malicious PDF document can trigger reuse of a previously freed object, which can lead to memory corruption and result in arbitrary code execution. An attacker needs to trick the user into opening the malicious file to trigger this vulnerability. Exploitation is also possible if a user visits a specially crafted, malicious site if the browser plugin extension is enabled.Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix a use-after-free There are two .exit_cmd_priv implementations. Both implementations use resources associated with the SCSI host. Make sure that these resources are still available when .exit_cmd_priv is called by waiting inside scsi_remove_host() until the tag set has been freed. This commit fixes the following use-after-free: ================================================================== BUG: KASAN: use-after-free in srp_exit_cmd_priv+0x27/0xd0 [ib_srp] Read of size 8 at addr ffff888100337000 by task multipathd/16727 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report.cold+0x5e/0x5db kasan_report+0xab/0x120 srp_exit_cmd_priv+0x27/0xd0 [ib_srp] scsi_mq_exit_request+0x4d/0x70 blk_mq_free_rqs+0x143/0x410 __blk_mq_free_map_and_rqs+0x6e/0x100 blk_mq_free_tag_set+0x2b/0x160 scsi_host_dev_release+0xf3/0x1a0 device_release+0x54/0xe0 kobject_put+0xa5/0x120 device_release+0x54/0xe0 kobject_put+0xa5/0x120 scsi_device_dev_release_usercontext+0x4c1/0x4e0 execute_in_process_context+0x23/0x90 device_release+0x54/0xe0 kobject_put+0xa5/0x120 scsi_disk_release+0x3f/0x50 device_release+0x54/0xe0 kobject_put+0xa5/0x120 disk_release+0x17f/0x1b0 device_release+0x54/0xe0 kobject_put+0xa5/0x120 dm_put_table_device+0xa3/0x160 [dm_mod] dm_put_device+0xd0/0x140 [dm_mod] free_priority_group+0xd8/0x110 [dm_multipath] free_multipath+0x94/0xe0 [dm_multipath] dm_table_destroy+0xa2/0x1e0 [dm_mod] __dm_destroy+0x196/0x350 [dm_mod] dev_remove+0x10c/0x160 [dm_mod] ctl_ioctl+0x2c2/0x590 [dm_mod] dm_ctl_ioctl+0x5/0x10 [dm_mod] __x64_sys_ioctl+0xb4/0xf0 dm_ctl_ioctl+0x5/0x10 [dm_mod] __x64_sys_ioctl+0xb4/0xf0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0Show less

In the Linux kernel, the following vulnerability has been resolved: mm/slab_common: fix possible double free of kmem_cache When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt'Show less

In the Linux kernel, the following vulnerability has been resolved: bnxt: prevent skb UAF after handing over to PTP worker When reading the timestamp is required bnxt_tx_int() hands over the ownership of the completed skb to the PTP worker. The skb should not be used afterwards, as the worker may run before the rest of our code and free the skb, leading to a use-after-free. Since dev_kfree_skb_any() accepts NULL make the loss of ownership more obvious and set skb to NULL.Show less

Use After Free vulnerability in Arm Ltd Bifrost GPU Kernel Driver, Arm Ltd Valhall GPU Kernel Driver, Arm Ltd Arm 5th Gen GPU Architecture Kernel Driver allows a local non-privileged user to make improper GPU memory processing operations to gain access to already freed memory.This issue affects Bifrost GPU Kernel Driver: from r45p0 through r48p0; Valhall GPU Kernel Driver: from r45p0 through r48p0; Arm 5th Gen GPU Architecture Kernel Driver: from r45p0 through r48p0. Show less