A vulnerability was found in the Linux kernel, where accessing a deallocated instance in printer_ioctl() printer_ioctl() tries to access of a printer_dev instance. However, use-after-free arises because it had been freed by gprinter_free().

An issue was discovered in the Linux kernel before 5.0. The function __mdiobus_register() in drivers/net/phy/mdio_bus.c calls put_device(), which will trigger a fixed_mdio_bus_init use-after-free. This will cause a denial of service.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix NULL ptr deref in crypto_aead_setkey() Neither SMB3.0 or SMB3.02 supports encryption negotiate context, so when SMB2_GLOBAL_CAP_ENCRYPTION flag is set in the negotiate response, the client uses AES-128-CCM as the default cipher. See MS-SMB2 3.3.5.4. Commit b0abcd65ec54 ("smb: client: fix UAF in async decryption") added a @server->cipher_type check to conditionally call smb3_crypto_aead_allocate(), but that check would always be false as @server->cipher_type is unset for SMB3.02. Fix the following KASAN splat by setting @server->cipher_type for SMB3.02 as well. mount.cifs //srv/share /mnt -o vers=3.02,seal,... BUG: KASAN: null-ptr-deref in crypto_aead_setkey+0x2c/0x130 Read of size 8 at addr 0000000000000020 by task mount.cifs/1095 CPU: 1 UID: 0 PID: 1095 Comm: mount.cifs Not tainted 6.12.0 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? crypto_aead_setkey+0x2c/0x130 kasan_report+0xda/0x110 ? crypto_aead_setkey+0x2c/0x130 crypto_aead_setkey+0x2c/0x130 crypt_message+0x258/0xec0 [cifs] ? __asan_memset+0x23/0x50 ? __pfx_crypt_message+0x10/0x10 [cifs] ? mark_lock+0xb0/0x6a0 ? hlock_class+0x32/0xb0 ? mark_lock+0xb0/0x6a0 smb3_init_transform_rq+0x352/0x3f0 [cifs] ? lock_acquire.part.0+0xf4/0x2a0 smb_send_rqst+0x144/0x230 [cifs] ? __pfx_smb_send_rqst+0x10/0x10 [cifs] ? hlock_class+0x32/0xb0 ? smb2_setup_request+0x225/0x3a0 [cifs] ? __pfx_cifs_compound_last_callback+0x10/0x10 [cifs] compound_send_recv+0x59b/0x1140 [cifs] ? __pfx_compound_send_recv+0x10/0x10 [cifs] ? __create_object+0x5e/0x90 ? hlock_class+0x32/0xb0 ? do_raw_spin_unlock+0x9a/0xf0 cifs_send_recv+0x23/0x30 [cifs] SMB2_tcon+0x3ec/0xb30 [cifs] ? __pfx_SMB2_tcon+0x10/0x10 [cifs] ? lock_acquire.part.0+0xf4/0x2a0 ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_trylock+0xc6/0x120 ? lock_acquire+0x3f/0x90 ? _get_xid+0x16/0xd0 [cifs] ? __pfx_SMB2_tcon+0x10/0x10 [cifs] ? cifs_get_smb_ses+0xcdd/0x10a0 [cifs] cifs_get_smb_ses+0xcdd/0x10a0 [cifs] ? __pfx_cifs_get_smb_ses+0x10/0x10 [cifs] ? cifs_get_tcp_session+0xaa0/0xca0 [cifs] cifs_mount_get_session+0x8a/0x210 [cifs] dfs_mount_share+0x1b0/0x11d0 [cifs] ? __pfx___lock_acquire+0x10/0x10 ? __pfx_dfs_mount_share+0x10/0x10 [cifs] ? lock_acquire.part.0+0xf4/0x2a0 ? find_held_lock+0x8a/0xa0 ? hlock_class+0x32/0xb0 ? lock_release+0x203/0x5d0 cifs_mount+0xb3/0x3d0 [cifs] ? do_raw_spin_trylock+0xc6/0x120 ? __pfx_cifs_mount+0x10/0x10 [cifs] ? lock_acquire+0x3f/0x90 ? find_nls+0x16/0xa0 ? smb3_update_mnt_flags+0x372/0x3b0 [cifs] cifs_smb3_do_mount+0x1e2/0xc80 [cifs] ? __pfx_vfs_parse_fs_string+0x10/0x10 ? __pfx_cifs_smb3_do_mount+0x10/0x10 [cifs] smb3_get_tree+0x1bf/0x330 [cifs] vfs_get_tree+0x4a/0x160 path_mount+0x3c1/0xfb0 ? kasan_quarantine_put+0xc7/0x1d0 ? __pfx_path_mount+0x10/0x10 ? kmem_cache_free+0x118/0x3e0 ? user_path_at+0x74/0xa0 __x64_sys_mount+0x1a6/0x1e0 ? __pfx___x64_sys_mount+0x10/0x10 ? mark_held_locks+0x1a/0x90 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

A use-after-free flaw was found in fs/ext4/namei.c:dx_insert_block() in the Linux kernel’s filesystem sub-component. This flaw allows a local attacker with a user privilege to cause a denial of service.

usb_8dev_start_xmit in drivers/net/can/usb/usb_8dev.c in the Linux kernel through 5.17.1 has a double free.

A Use After Free vulnerability in command processing of Juniper Networks Junos OS on MX Series allows a local, authenticated attacker to cause the broadband edge service manager daemon (bbe-smgd) to crash upon execution of specific CLI commands, creating a Denial of Service (DoS) condition.  The process crashes and restarts automatically. When specific CLI commands are executed, the bbe-smgd daemon attempts to write into an area of memory (mgd socket) that was already closed, causing the process to crash.  This process manages and controls the configuration of broadband subscriber sessions and services.  While the process is unavailable, additional subscribers will not be able to connect to the device, causing a temporary Denial of Service condition. This issue only occurs if Graceful Routing Engine Switchover (GRES) and Subscriber Management are enabled. This issue affects Junos OS: * All versions before 20.4R3-S5, * from 21.1 before 21.1R3-S4, * from 21.2 before 21.2R3-S3, * from 21.3 before 21.3R3-S5, * from 21.4 before 21.4R3-S5, * from 22.1 before 22.1R3, * from 22.2 before 22.2R3, * from 22.3 before 22.3R2;

mcba_usb_start_xmit in drivers/net/can/usb/mcba_usb.c in the Linux kernel through 5.17.1 has a double free.

A vulnerability has been found in HDF5 up to 1.14.6 and classified as problematic. This vulnerability affects the function H5MM_realloc of the file src/H5MM.c. The manipulation of the argument mem leads to double free. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.

A flaw was found in the Linux kernel's implementation of GRO in versions before 5.2. This flaw allows an attacker with local access to crash the system.

Use-after-free vulnerability in hw/pci/pcie.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (QEMU instance crash) via hotplug and hotunplug operations of Virtio block devices.

The __do_follow_link function in fs/namei.c in the Linux kernel before 2.6.33 does not properly handle the last pathname component during use of certain filesystems, which allows local users to cause a denial of service (incorrect free operations and system crash) via an open system call.

A NULL pointer dereference flaw was found in the Linux kernel’s X.25 set of standardized network protocols functionality in the way a user terminates their session using a simulated Ethernet card and continued usage of this connection. This flaw allows a local user to crash the system.

In libstagefright, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the media server with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-77474014

An issue was discovered in Falco through 0.14.0. A missing indicator for insufficient resources allows local users to bypass the detection engine.

QEMU 5.0.0 has a use-after-free in hw/usb/hcd-xhci.c because the usb_packet_map return value is not checked.

A component of the HarmonyOS has a Use After Free vulnerability. Local attackers may exploit this vulnerability to cause kernel crash.

There are use-after-free vulnerabilities caused by timer handler in net/rose/rose_timer.c of linux that allow attackers to crash linux kernel without any privileges.

In the Linux kernel, the following vulnerability has been resolved: x86/mm, kexec, ima: Use memblock_free_late() from ima_free_kexec_buffer() The code calling ima_free_kexec_buffer() runs long after the memblock allocator has already been torn down, potentially resulting in a use after free in memblock_isolate_range(). With KASAN or KFENCE, this use after free will result in a BUG from the idle task, and a subsequent kernel panic. Switch ima_free_kexec_buffer() over to memblock_free_late() to avoid that bug.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential use after free in nilfs_gccache_submit_read_data() In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the reference count of bh when the call to nilfs_dat_translate() fails. If the reference count hits 0 and its owner page gets unlocked, bh may be freed. However, bh->b_page is dereferenced to put the page after that, which may result in a use-after-free bug. This patch moves the release operation after unlocking and putting the page. NOTE: The function in question is only called in GC, and in combination with current userland tools, address translation using DAT does not occur in that function, so the code path that causes this issue will not be executed. However, it is possible to run that code path by intentionally modifying the userland GC library or by calling the GC ioctl directly. [konishi.ryusuke@gmail.com: NOTE added to the commit log]

In the Linux kernel, the following vulnerability has been resolved: ionic: fix kernel panic in XDP_TX action In the XDP_TX path, ionic driver sends a packet to the TX path with rx page and corresponding dma address. After tx is done, ionic_tx_clean() frees that page. But RX ring buffer isn't reset to NULL. So, it uses a freed page, which causes kernel panic. BUG: unable to handle page fault for address: ffff8881576c110c PGD 773801067 P4D 773801067 PUD 87f086067 PMD 87efca067 PTE 800ffffea893e060 Oops: Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN NOPTI CPU: 1 PID: 25 Comm: ksoftirqd/1 Not tainted 6.9.0+ #11 Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bpf_prog_f0b8caeac1068a55_balancer_ingress+0x3b/0x44f Code: 00 53 41 55 41 56 41 57 b8 01 00 00 00 48 8b 5f 08 4c 8b 77 00 4c 89 f7 48 83 c7 0e 48 39 d8 RSP: 0018:ffff888104e6fa28 EFLAGS: 00010283 RAX: 0000000000000002 RBX: ffff8881576c1140 RCX: 0000000000000002 RDX: ffffffffc0051f64 RSI: ffffc90002d33048 RDI: ffff8881576c110e RBP: ffff888104e6fa88 R08: 0000000000000000 R09: ffffed1027a04a23 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881b03a21a8 R13: ffff8881589f800f R14: ffff8881576c1100 R15: 00000001576c1100 FS: 0000000000000000(0000) GS:ffff88881ae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8881576c110c CR3: 0000000767a90000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x254/0x790 ? __pfx_page_fault_oops+0x10/0x10 ? __pfx_is_prefetch.constprop.0+0x10/0x10 ? search_bpf_extables+0x165/0x260 ? fixup_exception+0x4a/0x970 ? exc_page_fault+0xcb/0xe0 ? asm_exc_page_fault+0x22/0x30 ? 0xffffffffc0051f64 ? bpf_prog_f0b8caeac1068a55_balancer_ingress+0x3b/0x44f ? do_raw_spin_unlock+0x54/0x220 ionic_rx_service+0x11ab/0x3010 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? ionic_tx_clean+0x29b/0xc60 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_tx_clean+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_rx_service+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? ionic_tx_cq_service+0x25d/0xa00 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ? __pfx_ionic_rx_service+0x10/0x10 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ionic_cq_service+0x69/0x150 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] ionic_txrx_napi+0x11a/0x540 [ionic 9180c3001ab627d82bbc5f3ebe8a0decaf6bb864] __napi_poll.constprop.0+0xa0/0x440 net_rx_action+0x7e7/0xc30 ? __pfx_net_rx_action+0x10/0x10

A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

Use-after-Free vulnerability in cflow 1.6 in the void call(char *name, int line) function at src/parser.c, which could cause a denial of service via the pointer variable caller->callee.

Vim is an improved version of the good old UNIX editor Vi. Heap-use-after-free in memory allocated in the function `ga_grow_inner` in in the file `src/alloc.c` at line 748, which is freed in the file `src/ex_docmd.c` in the function `do_cmdline` at line 1010 and then used again in `src/cmdhist.c` at line 759. When using the `:history` command, it's possible that the provided argument overflows the accepted value. Causing an Integer Overflow and potentially later an use-after-free. This vulnerability has been patched in version 9.0.2068.

There is a double free vulnerability in some Huawei products. A local attacker with low privilege may perform some operations to exploit the vulnerability. Due to doubly freeing memory, successful exploit may cause some service abnormal. Affected product versions include:CampusInsight versions V100R019C00;ManageOne versions 6.5.RC2.B050.

The code in UEK6 U3 was missing an appropiate file descriptor count to be missing. This resulted in a use count error that allowed a file descriptor to a socket to be closed and freed while it was still in use by another portion of the kernel. An attack with local access can operate on the socket, and cause a denial of service. CVSS 3.1 Base Score 5.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

QEMU 4.2.0 has a use-after-free in hw/net/e1000e_core.c because a guest OS user can trigger an e1000e packet with the data's address set to the e1000e's MMIO address.

An issue was discovered in OpenEXR before 2.5.2. Invalid input could cause a use-after-free in DeepScanLineInputFile::DeepScanLineInputFile() in IlmImf/ImfDeepScanLineInputFile.cpp.

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix management of listener transports Currently, when no active threads are running, a root user using nfsdctl command can try to remove a particular listener from the list of previously added ones, then start the server by increasing the number of threads, it leads to the following problem: [ 158.835354] refcount_t: addition on 0; use-after-free. [ 158.835603] WARNING: CPU: 2 PID: 9145 at lib/refcount.c:25 refcount_warn_saturate+0x160/0x1a0 [ 158.836017] Modules linked in: rpcrdma rdma_cm iw_cm ib_cm ib_core nfsd auth_rpcgss nfs_acl lockd grace overlay isofs uinput snd_seq_dummy snd_hrtimer nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables qrtr sunrpc vfat fat uvcvideo videobuf2_vmalloc videobuf2_memops uvc videobuf2_v4l2 videodev videobuf2_common snd_hda_codec_generic mc e1000e snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore sg loop dm_multipath dm_mod nfnetlink vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vmw_vmci vsock xfs libcrc32c crct10dif_ce ghash_ce vmwgfx sha2_ce sha256_arm64 sr_mod sha1_ce cdrom nvme drm_client_lib drm_ttm_helper ttm nvme_core drm_kms_helper nvme_auth drm fuse [ 158.840093] CPU: 2 UID: 0 PID: 9145 Comm: nfsd Kdump: loaded Tainted: G B W 6.13.0-rc6+ #7 [ 158.840624] Tainted: [B]=BAD_PAGE, [W]=WARN [ 158.840802] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS VMW201.00V.24006586.BA64.2406042154 06/04/2024 [ 158.841220] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 158.841563] pc : refcount_warn_saturate+0x160/0x1a0 [ 158.841780] lr : refcount_warn_saturate+0x160/0x1a0 [ 158.842000] sp : ffff800089be7d80 [ 158.842147] x29: ffff800089be7d80 x28: ffff00008e68c148 x27: ffff00008e68c148 [ 158.842492] x26: ffff0002e3b5c000 x25: ffff600011cd1829 x24: ffff00008653c010 [ 158.842832] x23: ffff00008653c000 x22: 1fffe00011cd1829 x21: ffff00008653c028 [ 158.843175] x20: 0000000000000002 x19: ffff00008653c010 x18: 0000000000000000 [ 158.843505] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 158.843836] x14: 0000000000000000 x13: 0000000000000001 x12: ffff600050a26493 [ 158.844143] x11: 1fffe00050a26492 x10: ffff600050a26492 x9 : dfff800000000000 [ 158.844475] x8 : 00009fffaf5d9b6e x7 : ffff000285132493 x6 : 0000000000000001 [ 158.844823] x5 : ffff000285132490 x4 : ffff600050a26493 x3 : ffff8000805e72bc [ 158.845174] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000098588000 [ 158.845528] Call trace: [ 158.845658] refcount_warn_saturate+0x160/0x1a0 (P) [ 158.845894] svc_recv+0x58c/0x680 [sunrpc] [ 158.846183] nfsd+0x1fc/0x348 [nfsd] [ 158.846390] kthread+0x274/0x2f8 [ 158.846546] ret_from_fork+0x10/0x20 [ 158.846714] ---[ end trace 0000000000000000 ]--- nfsd_nl_listener_set_doit() would manipulate the list of transports of server's sv_permsocks and close the specified listener but the other list of transports (server's sp_xprts list) would not be changed leading to the problem above. Instead, determined if the nfsdctl is trying to remove a listener, in which case, delete all the existing listener transports and re-create all-but-the-removed ones.

In the Linux kernel, the following vulnerability has been resolved: mm/migrate_device: don't add folio to be freed to LRU in migrate_device_finalize() If migration succeeded, we called folio_migrate_flags()->mem_cgroup_migrate() to migrate the memcg from the old to the new folio. This will set memcg_data of the old folio to 0. Similarly, if migration failed, memcg_data of the dst folio is left unset. If we call folio_putback_lru() on such folios (memcg_data == 0), we will add the folio to be freed to the LRU, making memcg code unhappy. Running the hmm selftests: # ./hmm-tests ... # RUN hmm.hmm_device_private.migrate ... [ 102.078007][T14893] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x7ff27d200 pfn:0x13cc00 [ 102.079974][T14893] anon flags: 0x17ff00000020018(uptodate|dirty|swapbacked|node=0|zone=2|lastcpupid=0x7ff) [ 102.082037][T14893] raw: 017ff00000020018 dead000000000100 dead000000000122 ffff8881353896c9 [ 102.083687][T14893] raw: 00000007ff27d200 0000000000000000 00000001ffffffff 0000000000000000 [ 102.085331][T14893] page dumped because: VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled()) [ 102.087230][T14893] ------------[ cut here ]------------ [ 102.088279][T14893] WARNING: CPU: 0 PID: 14893 at ./include/linux/memcontrol.h:726 folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.090478][T14893] Modules linked in: [ 102.091244][T14893] CPU: 0 UID: 0 PID: 14893 Comm: hmm-tests Not tainted 6.13.0-09623-g6c216bc522fd #151 [ 102.093089][T14893] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 [ 102.094848][T14893] RIP: 0010:folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.096104][T14893] Code: ... [ 102.099908][T14893] RSP: 0018:ffffc900236c37b0 EFLAGS: 00010293 [ 102.101152][T14893] RAX: 0000000000000000 RBX: ffffea0004f30000 RCX: ffffffff8183f426 [ 102.102684][T14893] RDX: ffff8881063cb880 RSI: ffffffff81b8117f RDI: ffff8881063cb880 [ 102.104227][T14893] RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 [ 102.105757][T14893] R10: 0000000000000001 R11: 0000000000000002 R12: ffffc900236c37d8 [ 102.107296][T14893] R13: ffff888277a2bcb0 R14: 000000000000001f R15: 0000000000000000 [ 102.108830][T14893] FS: 00007ff27dbdd740(0000) GS:ffff888277a00000(0000) knlGS:0000000000000000 [ 102.110643][T14893] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 102.111924][T14893] CR2: 00007ff27d400000 CR3: 000000010866e000 CR4: 0000000000750ef0 [ 102.113478][T14893] PKRU: 55555554 [ 102.114172][T14893] Call Trace: [ 102.114805][T14893] <TASK> [ 102.115397][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.116547][T14893] ? __warn.cold+0x110/0x210 [ 102.117461][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.118667][T14893] ? report_bug+0x1b9/0x320 [ 102.119571][T14893] ? handle_bug+0x54/0x90 [ 102.120494][T14893] ? exc_invalid_op+0x17/0x50 [ 102.121433][T14893] ? asm_exc_invalid_op+0x1a/0x20 [ 102.122435][T14893] ? __wake_up_klogd.part.0+0x76/0xd0 [ 102.123506][T14893] ? dump_page+0x4f/0x60 [ 102.124352][T14893] ? folio_lruvec_lock_irqsave+0x10e/0x170 [ 102.125500][T14893] folio_batch_move_lru+0xd4/0x200 [ 102.126577][T14893] ? __pfx_lru_add+0x10/0x10 [ 102.127505][T14893] __folio_batch_add_and_move+0x391/0x720 [ 102.128633][T14893] ? __pfx_lru_add+0x10/0x10 [ 102.129550][T14893] folio_putback_lru+0x16/0x80 [ 102.130564][T14893] migrate_device_finalize+0x9b/0x530 [ 102.131640][T14893] dmirror_migrate_to_device.constprop.0+0x7c5/0xad0 [ 102.133047][T14893] dmirror_fops_unlocked_ioctl+0x89b/0xc80 Likely, nothing else goes wrong: putting the last folio reference will remove the folio from the LRU again. So besides memcg complaining, adding the folio to be freed to the LRU is just an unnecessary step. The new flow resembles what we have in migrate_folio_move(): add the dst to the lru, rem ---truncated---

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double free of TCP_Server_Info::hostname When shutting down the server in cifs_put_tcp_session(), cifsd thread might be reconnecting to multiple DFS targets before it realizes it should exit the loop, so @server->hostname can't be freed as long as cifsd thread isn't done. Otherwise the following can happen: RIP: 0010:__slab_free+0x223/0x3c0 Code: 5e 41 5f c3 cc cc cc cc 4c 89 de 4c 89 cf 44 89 44 24 08 4c 89 1c 24 e8 fb cf 8e 00 44 8b 44 24 08 4c 8b 1c 24 e9 5f fe ff ff <0f> 0b 41 f7 45 08 00 0d 21 00 0f 85 2d ff ff ff e9 1f ff ff ff 80 RSP: 0018:ffffb26180dbfd08 EFLAGS: 00010246 RAX: ffff8ea34728e510 RBX: ffff8ea34728e500 RCX: 0000000000800068 RDX: 0000000000800068 RSI: 0000000000000000 RDI: ffff8ea340042400 RBP: ffffe112041ca380 R08: 0000000000000001 R09: 0000000000000000 R10: 6170732e31303000 R11: 70726f632e786563 R12: ffff8ea34728e500 R13: ffff8ea340042400 R14: ffff8ea34728e500 R15: 0000000000800068 FS: 0000000000000000(0000) GS:ffff8ea66fd80000(0000) 000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc25376080 CR3: 000000012a2ba001 CR4: PKRU: 55555554 Call Trace: <TASK> ? show_trace_log_lvl+0x1c4/0x2df ? show_trace_log_lvl+0x1c4/0x2df ? __reconnect_target_unlocked+0x3e/0x160 [cifs] ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0xce/0x120 ? __slab_free+0x223/0x3c0 ? do_error_trap+0x65/0x80 ? __slab_free+0x223/0x3c0 ? exc_invalid_op+0x4e/0x70 ? __slab_free+0x223/0x3c0 ? asm_exc_invalid_op+0x16/0x20 ? __slab_free+0x223/0x3c0 ? extract_hostname+0x5c/0xa0 [cifs] ? extract_hostname+0x5c/0xa0 [cifs] ? __kmalloc+0x4b/0x140 __reconnect_target_unlocked+0x3e/0x160 [cifs] reconnect_dfs_server+0x145/0x430 [cifs] cifs_handle_standard+0x1ad/0x1d0 [cifs] cifs_demultiplex_thread+0x592/0x730 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0xdd/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 </TASK>

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix a use-after-free looks like we forget to set ttm->sg to NULL. Hit panic below [ 1235.844104] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b7b4b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 1235.989074] Call Trace: [ 1235.991751] sg_free_table+0x17/0x20 [ 1235.995667] amdgpu_ttm_backend_unbind.cold+0x4d/0xf7 [amdgpu] [ 1236.002288] amdgpu_ttm_backend_destroy+0x29/0x130 [amdgpu] [ 1236.008464] ttm_tt_destroy+0x1e/0x30 [ttm] [ 1236.013066] ttm_bo_cleanup_memtype_use+0x51/0xa0 [ttm] [ 1236.018783] ttm_bo_release+0x262/0xa50 [ttm] [ 1236.023547] ttm_bo_put+0x82/0xd0 [ttm] [ 1236.027766] amdgpu_bo_unref+0x26/0x50 [amdgpu] [ 1236.032809] amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu+0x7aa/0xd90 [amdgpu] [ 1236.040400] kfd_ioctl_alloc_memory_of_gpu+0xe2/0x330 [amdgpu] [ 1236.046912] kfd_ioctl+0x463/0x690 [amdgpu]

In the Linux kernel, the following vulnerability has been resolved: userfaultfd: release page in error path to avoid BUG_ON Consider the following sequence of events: 1. Userspace issues a UFFD ioctl, which ends up calling into shmem_mfill_atomic_pte(). We successfully account the blocks, we shmem_alloc_page(), but then the copy_from_user() fails. We return -ENOENT. We don't release the page we allocated. 2. Our caller detects this error code, tries the copy_from_user() after dropping the mmap_lock, and retries, calling back into shmem_mfill_atomic_pte(). 3. Meanwhile, let's say another process filled up the tmpfs being used. 4. So shmem_mfill_atomic_pte() fails to account blocks this time, and immediately returns - without releasing the page. This triggers a BUG_ON in our caller, which asserts that the page should always be consumed, unless -ENOENT is returned. To fix this, detect if we have such a "dangling" page when accounting fails, and if so, release it before returning.

In the Linux kernel, the following vulnerability has been resolved: sched/fair: Prevent dead task groups from regaining cfs_rq's Kevin is reporting crashes which point to a use-after-free of a cfs_rq in update_blocked_averages(). Initial debugging revealed that we've live cfs_rq's (on_list=1) in an about to be kfree()'d task group in free_fair_sched_group(). However, it was unclear how that can happen. His kernel config happened to lead to a layout of struct sched_entity that put the 'my_q' member directly into the middle of the object which makes it incidentally overlap with SLUB's freelist pointer. That, in combination with SLAB_FREELIST_HARDENED's freelist pointer mangling, leads to a reliable access violation in form of a #GP which made the UAF fail fast. Michal seems to have run into the same issue[1]. He already correctly diagnosed that commit a7b359fc6a37 ("sched/fair: Correctly insert cfs_rq's to list on unthrottle") is causing the preconditions for the UAF to happen by re-adding cfs_rq's also to task groups that have no more running tasks, i.e. also to dead ones. His analysis, however, misses the real root cause and it cannot be seen from the crash backtrace only, as the real offender is tg_unthrottle_up() getting called via sched_cfs_period_timer() via the timer interrupt at an inconvenient time. When unregister_fair_sched_group() unlinks all cfs_rq's from the dying task group, it doesn't protect itself from getting interrupted. If the timer interrupt triggers while we iterate over all CPUs or after unregister_fair_sched_group() has finished but prior to unlinking the task group, sched_cfs_period_timer() will execute and walk the list of task groups, trying to unthrottle cfs_rq's, i.e. re-add them to the dying task group. These will later -- in free_fair_sched_group() -- be kfree()'ed while still being linked, leading to the fireworks Kevin and Michal are seeing. To fix this race, ensure the dying task group gets unlinked first. However, simply switching the order of unregistering and unlinking the task group isn't sufficient, as concurrent RCU walkers might still see it, as can be seen below: CPU1: CPU2: : timer IRQ: : do_sched_cfs_period_timer(): : : : distribute_cfs_runtime(): : rcu_read_lock(); : : : unthrottle_cfs_rq(): sched_offline_group(): : : walk_tg_tree_from(…,tg_unthrottle_up,…): list_del_rcu(&tg->list); : (1) : list_for_each_entry_rcu(child, &parent->children, siblings) : : (2) list_del_rcu(&tg->siblings); : : tg_unthrottle_up(): unregister_fair_sched_group(): struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; : : list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); : : : : if (!cfs_rq_is_decayed(cfs_rq) || cfs_rq->nr_running) (3) : list_add_leaf_cfs_rq(cfs_rq); : : : : : : : : : ---truncated---

In the Linux kernel, the following vulnerability has been resolved: spi: fix use-after-free of the add_lock mutex Commit 6098475d4cb4 ("spi: Fix deadlock when adding SPI controllers on SPI buses") introduced a per-controller mutex. But mutex_unlock() of said lock is called after the controller is already freed: spi_unregister_controller(ctlr) -> put_device(&ctlr->dev) -> spi_controller_release(dev) -> mutex_unlock(&ctrl->add_lock) Move the put_device() after the mutex_unlock().

In the Linux kernel, the following vulnerability has been resolved: tipc: skb_linearize the head skb when reassembling msgs It's not a good idea to append the frag skb to a skb's frag_list if the frag_list already has skbs from elsewhere, such as this skb was created by pskb_copy() where the frag_list was cloned (all the skbs in it were skb_get'ed) and shared by multiple skbs. However, the new appended frag skb should have been only seen by the current skb. Otherwise, it will cause use after free crashes as this appended frag skb are seen by multiple skbs but it only got skb_get called once. The same thing happens with a skb updated by pskb_may_pull() with a skb_cloned skb. Li Shuang has reported quite a few crashes caused by this when doing testing over macvlan devices: [] kernel BUG at net/core/skbuff.c:1970! [] Call Trace: [] skb_clone+0x4d/0xb0 [] macvlan_broadcast+0xd8/0x160 [macvlan] [] macvlan_process_broadcast+0x148/0x150 [macvlan] [] process_one_work+0x1a7/0x360 [] worker_thread+0x30/0x390 [] kernel BUG at mm/usercopy.c:102! [] Call Trace: [] __check_heap_object+0xd3/0x100 [] __check_object_size+0xff/0x16b [] simple_copy_to_iter+0x1c/0x30 [] __skb_datagram_iter+0x7d/0x310 [] __skb_datagram_iter+0x2a5/0x310 [] skb_copy_datagram_iter+0x3b/0x90 [] tipc_recvmsg+0x14a/0x3a0 [tipc] [] ____sys_recvmsg+0x91/0x150 [] ___sys_recvmsg+0x7b/0xc0 [] kernel BUG at mm/slub.c:305! [] Call Trace: [] <IRQ> [] kmem_cache_free+0x3ff/0x400 [] __netif_receive_skb_core+0x12c/0xc40 [] ? kmem_cache_alloc+0x12e/0x270 [] netif_receive_skb_internal+0x3d/0xb0 [] ? get_rx_page_info+0x8e/0xa0 [be2net] [] be_poll+0x6ef/0xd00 [be2net] [] ? irq_exit+0x4f/0x100 [] net_rx_action+0x149/0x3b0 ... This patch is to fix it by linearizing the head skb if it has frag_list set in tipc_buf_append(). Note that we choose to do this before calling skb_unshare(), as __skb_linearize() will avoid skb_copy(). Also, we can not just drop the frag_list either as the early time.

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Free gadget structure only after freeing endpoints As part of commit e81a7018d93a ("usb: dwc3: allocate gadget structure dynamically") the dwc3_gadget_release() was added which will free the dwc->gadget structure upon the device's removal when usb_del_gadget_udc() is called in dwc3_gadget_exit(). However, simply freeing the gadget results a dangling pointer situation: the endpoints created in dwc3_gadget_init_endpoints() have their dep->endpoint.ep_list members chained off the list_head anchored at dwc->gadget->ep_list. Thus when dwc->gadget is freed, the first dwc3_ep in the list now has a dangling prev pointer and likewise for the next pointer of the dwc3_ep at the tail of the list. The dwc3_gadget_free_endpoints() that follows will result in a use-after-free when it calls list_del(). This was caught by enabling KASAN and performing a driver unbind. The recent commit 568262bf5492 ("usb: dwc3: core: Add shutdown callback for dwc3") also exposes this as a panic during shutdown. There are a few possibilities to fix this. One could be to perform a list_del() of the gadget->ep_list itself which removes it from the rest of the dwc3_ep chain. Another approach is what this patch does, by splitting up the usb_del_gadget_udc() call into its separate "del" and "put" components. This allows dwc3_gadget_free_endpoints() to be called before the gadget is finally freed with usb_put_gadget().

A vulnerability was found in GPAC 2.5-DEV-rev228-g11067ea92-master. It has been declared as problematic. This vulnerability affects the function xmt_node_end of the file src/scene_manager/loader_xmt.c of the component MP4Box. The manipulation leads to use after free. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used. The name of the patch is f4b3e4d2f91bc1749e7a924a8ab171af03a355a8/c1b9c794bad8f262c56f3cf690567980d96662f5. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-268792.

A use-after-free vulnerability was found in the Linux kernel in drivers/net/hamradio. This flaw allows a local attacker with a user privilege to cause a denial of service (DOS) when the mkiss or sixpack device is detached and reclaim resources early.

A use-after-free flaw was found in the Linux kernel’s Amateur Radio AX.25 protocol functionality in the way a user connects with the protocol. This flaw allows a local user to crash the system.

In the Linux kernel, the following vulnerability has been resolved: ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).

Use after free in some Intel(R) Graphics Drivers before version 15.33.51.5146 may allow an authenticated user to potentially enable denial of service via local access.

A use-after-free flaw was found in reconn_set_ipaddr_from_hostname in fs/cifs/connect.c in the Linux kernel. The issue occurs when it forgets to set the free pointer server->hostname to NULL, leading to an invalid pointer request.

Vixie Cron before the 3.0pl1-133 Debian package allows local users to cause a denial of service (use-after-free and daemon crash) because of a force_rescan_user error.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix double free during GPU reset on DC streams [Why] The issue only occurs during the GPU reset code path. We first backup the current state prior to commiting 0 streams internally from DM to DC. This state backup contains valid link encoder assignments. DC will clear the link encoder assignments as part of current state (but not the backup, since it was a copied before the commit) and free the extra stream reference it held. DC requires that the link encoder assignments remain cleared/invalid prior to commiting. Since the backup still has valid assignments we call the interface post reset to clear them. This routine also releases the extra reference that the link encoder interface held - resulting in a double free (and eventually a NULL pointer dereference). [How] We'll have to do a full DC commit anyway after GPU reset because the stream count previously went to 0. We don't need to retain the assignment that we had backed up, so just copy off of the now clean current state assignment after the reset has occcurred with the new link_enc_cfg_copy() interface.

An issue was discovered in the Linux kernel through 6.4.2. A crafted UDF filesystem image causes a use-after-free write operation in the udf_put_super and udf_close_lvid functions in fs/udf/super.c. NOTE: the suse.com reference has a different perspective about this.

In the Linux kernel, the following vulnerability has been resolved: net: microchip: vcap api: Fix memory leaks in vcap_api_encode_rule_test() Commit a3c1e45156ad ("net: microchip: vcap: Fix use-after-free error in kunit test") fixed the use-after-free error, but introduced below memory leaks by removing necessary vcap_free_rule(), add it to fix it. unreferenced object 0xffffff80ca58b700 (size 192): comm "kunit_try_catch", pid 1215, jiffies 4294898264 hex dump (first 32 bytes): 00 12 7a 00 05 00 00 00 0a 00 00 00 64 00 00 00 ..z.........d... 00 00 00 00 00 00 00 00 00 04 0b cc 80 ff ff ff ................ backtrace (crc 9c09c3fe): [<0000000052a0be73>] kmemleak_alloc+0x34/0x40 [<0000000043605459>] __kmalloc_cache_noprof+0x26c/0x2f4 [<0000000040a01b8d>] vcap_alloc_rule+0x3cc/0x9c4 [<000000003fe86110>] vcap_api_encode_rule_test+0x1ac/0x16b0 [<00000000b3595fc4>] kunit_try_run_case+0x13c/0x3ac [<0000000010f5d2bf>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000c5d82c9a>] kthread+0x2e8/0x374 [<00000000f4287308>] ret_from_fork+0x10/0x20 unreferenced object 0xffffff80cc0b0400 (size 64): comm "kunit_try_catch", pid 1215, jiffies 4294898265 hex dump (first 32 bytes): 80 04 0b cc 80 ff ff ff 18 b7 58 ca 80 ff ff ff ..........X..... 39 00 00 00 02 00 00 00 06 05 04 03 02 01 ff ff 9............... backtrace (crc daf014e9): [<0000000052a0be73>] kmemleak_alloc+0x34/0x40 [<0000000043605459>] __kmalloc_cache_noprof+0x26c/0x2f4 [<000000000ff63fd4>] vcap_rule_add_key+0x2cc/0x528 [<00000000dfdb1e81>] vcap_api_encode_rule_test+0x224/0x16b0 [<00000000b3595fc4>] kunit_try_run_case+0x13c/0x3ac [<0000000010f5d2bf>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000c5d82c9a>] kthread+0x2e8/0x374 [<00000000f4287308>] ret_from_fork+0x10/0x20 unreferenced object 0xffffff80cc0b0700 (size 64): comm "kunit_try_catch", pid 1215, jiffies 4294898265 hex dump (first 32 bytes): 80 07 0b cc 80 ff ff ff 28 b7 58 ca 80 ff ff ff ........(.X..... 3c 00 00 00 00 00 00 00 01 2f 03 b3 ec ff ff ff <......../...... backtrace (crc 8d877792): [<0000000052a0be73>] kmemleak_alloc+0x34/0x40 [<0000000043605459>] __kmalloc_cache_noprof+0x26c/0x2f4 [<000000006eadfab7>] vcap_rule_add_action+0x2d0/0x52c [<00000000323475d1>] vcap_api_encode_rule_test+0x4d4/0x16b0 [<00000000b3595fc4>] kunit_try_run_case+0x13c/0x3ac [<0000000010f5d2bf>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000c5d82c9a>] kthread+0x2e8/0x374 [<00000000f4287308>] ret_from_fork+0x10/0x20 unreferenced object 0xffffff80cc0b0900 (size 64): comm "kunit_try_catch", pid 1215, jiffies 4294898266 hex dump (first 32 bytes): 80 09 0b cc 80 ff ff ff 80 06 0b cc 80 ff ff ff ................ 7d 00 00 00 01 00 00 00 00 00 00 00 ff 00 00 00 }............... backtrace (crc 34181e56): [<0000000052a0be73>] kmemleak_alloc+0x34/0x40 [<0000000043605459>] __kmalloc_cache_noprof+0x26c/0x2f4 [<000000000ff63fd4>] vcap_rule_add_key+0x2cc/0x528 [<00000000991e3564>] vcap_val_rule+0xcf0/0x13e8 [<00000000fc9868e5>] vcap_api_encode_rule_test+0x678/0x16b0 [<00000000b3595fc4>] kunit_try_run_case+0x13c/0x3ac [<0000000010f5d2bf>] kunit_generic_run_threadfn_adapter+0x80/0xec [<00000000c5d82c9a>] kthread+0x2e8/0x374 [<00000000f4287308>] ret_from_fork+0x10/0x20 unreferenced object 0xffffff80cc0b0980 (size 64): comm "kunit_try_catch", pid 1215, jiffies 4294898266 hex dump (first 32 bytes): 18 b7 58 ca 80 ff ff ff 00 09 0b cc 80 ff ff ff ..X............. 67 00 00 00 00 00 00 00 01 01 74 88 c0 ff ff ff g.........t..... backtrace (crc 275fd9be): [<0000000052a0be73>] kmemleak_alloc+0x34/0x40 [<0000000043605459>] __kmalloc_cache_noprof+0x26c/0x2f4 [<000000000ff63fd4>] vcap_rule_add_key+0x2cc/0x528 [<000000001396a1a2>] test_add_de ---truncated---

In the Linux kernel, the following vulnerability has been resolved: btrfs: wait for fixup workers before stopping cleaner kthread during umount During unmount, at close_ctree(), we have the following steps in this order: 1) Park the cleaner kthread - this doesn't destroy the kthread, it basically halts its execution (wake ups against it work but do nothing); 2) We stop the cleaner kthread - this results in freeing the respective struct task_struct; 3) We call btrfs_stop_all_workers() which waits for any jobs running in all the work queues and then free the work queues. Syzbot reported a case where a fixup worker resulted in a crash when doing a delayed iput on its inode while attempting to wake up the cleaner at btrfs_add_delayed_iput(), because the task_struct of the cleaner kthread was already freed. This can happen during unmount because we don't wait for any fixup workers still running before we call kthread_stop() against the cleaner kthread, which stops and free all its resources. Fix this by waiting for any fixup workers at close_ctree() before we call kthread_stop() against the cleaner and run pending delayed iputs. The stack traces reported by syzbot were the following: BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065 Read of size 8 at addr ffff8880272a8a18 by task kworker/u8:3/52 CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: btrfs-fixup btrfs_work_helper Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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 __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4154 btrfs_writepage_fixup_worker+0xc16/0xdf0 fs/btrfs/inode.c:2842 btrfs_work_helper+0x390/0xc50 fs/btrfs/async-thread.c:314 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 2: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187 alloc_task_struct_node kernel/fork.c:180 [inline] dup_task_struct+0x57/0x8c0 kernel/fork.c:1107 copy_process+0x5d1/0x3d50 kernel/fork.c:2206 kernel_clone+0x223/0x880 kernel/fork.c:2787 kernel_thread+0x1bc/0x240 kernel/fork.c:2849 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:765 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 61: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_h ---truncated---

In the Linux kernel, the following vulnerability has been resolved: sctp: use call_rcu to free endpoint This patch is to delay the endpoint free by calling call_rcu() to fix another use-after-free issue in sctp_sock_dump(): BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20 Call Trace: __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] __lock_sock+0x203/0x350 net/core/sock.c:2253 lock_sock_nested+0xfe/0x120 net/core/sock.c:2774 lock_sock include/net/sock.h:1492 [inline] sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324 sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091 sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527 __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065 netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:216 [inline] inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170 __sock_diag_cmd net/core/sock_diag.c:232 [inline] sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274 This issue occurs when asoc is peeled off and the old sk is freed after getting it by asoc->base.sk and before calling lock_sock(sk). To prevent the sk free, as a holder of the sk, ep should be alive when calling lock_sock(). This patch uses call_rcu() and moves sock_put and ep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to hold the ep under rcu_read_lock in sctp_transport_traverse_process(). If sctp_endpoint_hold() returns true, it means this ep is still alive and we have held it and can continue to dump it; If it returns false, it means this ep is dead and can be freed after rcu_read_unlock, and we should skip it. In sctp_sock_dump(), after locking the sk, if this ep is different from tsp->asoc->ep, it means during this dumping, this asoc was peeled off before calling lock_sock(), and the sk should be skipped; If this ep is the same with tsp->asoc->ep, it means no peeloff happens on this asoc, and due to lock_sock, no peeloff will happen either until release_sock. Note that delaying endpoint free won't delay the port release, as the port release happens in sctp_endpoint_destroy() before calling call_rcu(). Also, freeing endpoint by call_rcu() makes it safe to access the sk by asoc->base.sk in sctp_assocs_seq_show() and sctp_rcv(). Thanks Jones to bring this issue up. v1->v2: - improve the changelog. - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed.

In the Linux kernel, the following vulnerability has been resolved: net/ncsi: Disable the ncsi work before freeing the associated structure The work function can run after the ncsi device is freed, resulting in use-after-free bugs or kernel panic.

In the Linux kernel, the following vulnerability has been resolved: xdp, net: Fix use-after-free in bpf_xdp_link_release The problem occurs between dev_get_by_index() and dev_xdp_attach_link(). At this point, dev_xdp_uninstall() is called. Then xdp link will not be detached automatically when dev is released. But link->dev already points to dev, when xdp link is released, dev will still be accessed, but dev has been released. dev_get_by_index() | link->dev = dev | | rtnl_lock() | unregister_netdevice_many() | dev_xdp_uninstall() | rtnl_unlock() rtnl_lock(); | dev_xdp_attach_link() | rtnl_unlock(); | | netdev_run_todo() // dev released bpf_xdp_link_release() | /* access dev. | use-after-free */ | [ 45.966867] BUG: KASAN: use-after-free in bpf_xdp_link_release+0x3b8/0x3d0 [ 45.967619] Read of size 8 at addr ffff00000f9980c8 by task a.out/732 [ 45.968297] [ 45.968502] CPU: 1 PID: 732 Comm: a.out Not tainted 5.13.0+ #22 [ 45.969222] Hardware name: linux,dummy-virt (DT) [ 45.969795] Call trace: [ 45.970106] dump_backtrace+0x0/0x4c8 [ 45.970564] show_stack+0x30/0x40 [ 45.970981] dump_stack_lvl+0x120/0x18c [ 45.971470] print_address_description.constprop.0+0x74/0x30c [ 45.972182] kasan_report+0x1e8/0x200 [ 45.972659] __asan_report_load8_noabort+0x2c/0x50 [ 45.973273] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.973834] bpf_link_free+0xd0/0x188 [ 45.974315] bpf_link_put+0x1d0/0x218 [ 45.974790] bpf_link_release+0x3c/0x58 [ 45.975291] __fput+0x20c/0x7e8 [ 45.975706] ____fput+0x24/0x30 [ 45.976117] task_work_run+0x104/0x258 [ 45.976609] do_notify_resume+0x894/0xaf8 [ 45.977121] work_pending+0xc/0x328 [ 45.977575] [ 45.977775] The buggy address belongs to the page: [ 45.978369] page:fffffc00003e6600 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4f998 [ 45.979522] flags: 0x7fffe0000000000(node=0|zone=0|lastcpupid=0x3ffff) [ 45.980349] raw: 07fffe0000000000 fffffc00003e6708 ffff0000dac3c010 0000000000000000 [ 45.981309] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 45.982259] page dumped because: kasan: bad access detected [ 45.982948] [ 45.983153] Memory state around the buggy address: [ 45.983753] ffff00000f997f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 45.984645] ffff00000f998000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.985533] >ffff00000f998080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.986419] ^ [ 45.987112] ffff00000f998100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988006] ffff00000f998180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 45.988895] ================================================================== [ 45.989773] Disabling lock debugging due to kernel taint [ 45.990552] Kernel panic - not syncing: panic_on_warn set ... [ 45.991166] CPU: 1 PID: 732 Comm: a.out Tainted: G B 5.13.0+ #22 [ 45.991929] Hardware name: linux,dummy-virt (DT) [ 45.992448] Call trace: [ 45.992753] dump_backtrace+0x0/0x4c8 [ 45.993208] show_stack+0x30/0x40 [ 45.993627] dump_stack_lvl+0x120/0x18c [ 45.994113] dump_stack+0x1c/0x34 [ 45.994530] panic+0x3a4/0x7d8 [ 45.994930] end_report+0x194/0x198 [ 45.995380] kasan_report+0x134/0x200 [ 45.995850] __asan_report_load8_noabort+0x2c/0x50 [ 45.996453] bpf_xdp_link_release+0x3b8/0x3d0 [ 45.997007] bpf_link_free+0xd0/0x188 [ 45.997474] bpf_link_put+0x1d0/0x218 [ 45.997942] bpf_link_release+0x3c/0x58 [ 45.998429] __fput+0x20c/0x7e8 [ 45.998833] ____fput+0x24/0x30 [ 45.999247] task_work_run+0x104/0x258 [ 45.999731] do_notify_resume+0x894/0xaf8 [ 46.000236] work_pending ---truncated---