Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: Revert "smb: client: fix TCP timers deadlock after rmmod" This reverts commit e9f2517a3e18a54a3943c098d2226b245d488801. Commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod") is intended to fix a null-ptr-deref in LOCKDEP, which is mentioned as CVE-2024-54680, but is actually did not fix anything; The issue can be reproduced on top of it. [0] Also, it reverted the change by commit ef7134c7fc48 ("smb: client: Fix use-after-free of network namespace.") and introduced a real issue by reviving the kernel TCP socket. When a reconnect happens for a CIFS connection, the socket state transitions to FIN_WAIT_1. Then, inet_csk_clear_xmit_timers_sync() in tcp_close() stops all timers for the socket. If an incoming FIN packet is lost, the socket will stay at FIN_WAIT_1 forever, and such sockets could be leaked up to net.ipv4.tcp_max_orphans. Usually, FIN can be retransmitted by the peer, but if the peer aborts the connection, the issue comes into reality. I warned about this privately by pointing out the exact report [1], but the bogus fix was finally merged. So, we should not stop the timers to finally kill the connection on our side in that case, meaning we must not use a kernel socket for TCP whose sk->sk_net_refcnt is 0. The kernel socket does not have a reference to its netns to make it possible to tear down netns without cleaning up every resource in it. For example, tunnel devices use a UDP socket internally, but we can destroy netns without removing such devices and let it complete during exit. Otherwise, netns would be leaked when the last application died. However, this is problematic for TCP sockets because TCP has timers to close the connection gracefully even after the socket is close()d. The lifetime of the socket and its netns is different from the lifetime of the underlying connection. If the socket user does not maintain the netns lifetime, the timer could be fired after the socket is close()d and its netns is freed up, resulting in use-after-free. Actually, we have seen so many similar issues and converted such sockets to have a reference to netns. That's why I converted the CIFS client socket to have a reference to netns (sk->sk_net_refcnt == 1), which is somehow mentioned as out-of-scope of CIFS and technically wrong in e9f2517a3e18, but **is in-scope and right fix**. Regarding the LOCKDEP issue, we can prevent the module unload by bumping the module refcount when switching the LOCKDDEP key in sock_lock_init_class_and_name(). [2] For a while, let's revert the bogus fix. Note that now we can use sk_net_refcnt_upgrade() for the socket conversion, but I'll do so later separately to make backport easy.Show less

In the Linux kernel, the following vulnerability has been resolved: exfat: fix missing shutdown check xfstests generic/730 test failed because after deleting the device that still had dirty data, the file could still be read without returning an error. The reason is the missing shutdown check in ->read_iter. I also noticed that shutdown checks were missing from ->write_iter, ->splice_read, and ->mmap. This commit adds shutdown checks to all of them.Show less

In the Linux kernel, the following vulnerability has been resolved: rtnetlink: Allocate vfinfo size for VF GUIDs when supported Commit 30aad41721e0 ("net/core: Add support for getting VF GUIDs") added support for getting VF port and node GUIDs in netlink ifinfo messages, but their size was not taken into consideration in the function that allocates the netlink message, causing the following warning when a netlink message is filled with many VF port and node GUIDs: # echo 64 > /sys/bus/pci/devices/0000\:08\:00.0/sriov_numvfs # ip link show dev ib0 RTNETLINK answers: Message too long Cannot send link get request: Message too long Kernel warning: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1930 at net/core/rtnetlink.c:4151 rtnl_getlink+0x586/0x5a0 Modules linked in: xt_conntrack xt_MASQUERADE nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter overlay mlx5_ib macsec mlx5_core tls rpcrdma rdma_ucm ib_uverbs ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm iw_cm ib_ipoib fuse ib_cm ib_core CPU: 2 UID: 0 PID: 1930 Comm: ip Not tainted 6.14.0-rc2+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:rtnl_getlink+0x586/0x5a0 Code: cb 82 e8 3d af 0a 00 4d 85 ff 0f 84 08 ff ff ff 4c 89 ff 41 be ea ff ff ff e8 66 63 5b ff 49 c7 07 80 4f cb 82 e9 36 fc ff ff <0f> 0b e9 16 fe ff ff e8 de a0 56 00 66 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffff888113557348 EFLAGS: 00010246 RAX: 00000000ffffffa6 RBX: ffff88817e87aa34 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88817e87afb8 RBP: 0000000000000009 R08: ffffffff821f44aa R09: 0000000000000000 R10: ffff8881260f79a8 R11: ffff88817e87af00 R12: ffff88817e87aa00 R13: ffffffff8563d300 R14: 00000000ffffffa6 R15: 00000000ffffffff FS: 00007f63a5dbf280(0000) GS:ffff88881ee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f63a5ba4493 CR3: 00000001700fe002 CR4: 0000000000772eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __warn+0xa5/0x230 ? rtnl_getlink+0x586/0x5a0 ? report_bug+0x22d/0x240 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x14/0x50 ? asm_exc_invalid_op+0x16/0x20 ? skb_trim+0x6a/0x80 ? rtnl_getlink+0x586/0x5a0 ? __pfx_rtnl_getlink+0x10/0x10 ? rtnetlink_rcv_msg+0x1e5/0x860 ? __pfx___mutex_lock+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? __pfx_lock_acquire+0x10/0x10 ? stack_trace_save+0x90/0xd0 ? filter_irq_stacks+0x1d/0x70 ? kasan_save_stack+0x30/0x40 ? kasan_save_stack+0x20/0x40 ? kasan_save_track+0x10/0x30 rtnetlink_rcv_msg+0x21c/0x860 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e ? __pfx_rtnetlink_rcv_msg+0x10/0x10 ? arch_stack_walk+0x9e/0xf0 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd5/0x410 ? rcu_is_watching+0x34/0x60 netlink_rcv_skb+0xe0/0x210 ? __pfx_rtnetlink_rcv_msg+0x10/0x10 ? __pfx_netlink_rcv_skb+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? __pfx___netlink_lookup+0x10/0x10 ? lock_release+0x62/0x200 ? netlink_deliver_tap+0xfd/0x290 ? rcu_is_watching+0x34/0x60 ? lock_release+0x62/0x200 ? netlink_deliver_tap+0x95/0x290 netlink_unicast+0x31f/0x480 ? __pfx_netlink_unicast+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd5/0x410 netlink_sendmsg+0x369/0x660 ? lock_release+0x62/0x200 ? __pfx_netlink_sendmsg+0x10/0x10 ? import_ubuf+0xb9/0xf0 ? __import_iovec+0x254/0x2b0 ? lock_release+0x62/0x200 ? __pfx_netlink_sendmsg+0x10/0x10 ____sys_sendmsg+0x559/0x5a0 ? __pfx_____sys_sendmsg+0x10/0x10 ? __pfx_copy_msghdr_from_user+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? do_read_fault+0x213/0x4a0 ? rcu_is_watching+0x34/0x60 ___sys_sendmsg+0xe4/0x150 ? __pfx____sys_sendmsg+0x10/0x10 ? do_fault+0x2cc/0x6f0 ? handle_pte_fault+0x2e3/0x3d0 ? __pfx_handle_pte_fault+0x10/0x10 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix r_count dec/increment mismatch r_count is only increased when there is an oplock break wait, so r_count inc/decrement are not paired. This can cause r_count to become negative, which can lead to a problem where the ksmbd thread does not terminate.Show less

In the Linux kernel, the following vulnerability has been resolved: spufs: fix a leak on spufs_new_file() failure It's called from spufs_fill_dir(), and caller of that will do spufs_rmdir() in case of failure. That does remove everything we'd managed to create, but... the problem dentry is still negative. IOW, it needs to be explicitly dropped.Show less

In the Linux kernel, the following vulnerability has been resolved: spufs: fix gang directory lifetimes prior to "[POWERPC] spufs: Fix gang destroy leaks" we used to have a problem with gang lifetimes - creation of a gang returns opened gang directory, which normally gets removed when that gets closed, but if somebody has created a context belonging to that gang and kept it alive until the gang got closed, removal failed and we ended up with a leak. Unfortunately, it had been fixed the wrong way. Dentry of gang directory was no longer pinned, and rmdir on close was gone. One problem was that failure of open kept calling simple_rmdir() as cleanup, which meant an unbalanced dput(). Another bug was in the success case - gang creation incremented link count on root directory, but that was no longer undone when gang got destroyed. Fix consists of * reverting the commit in question * adding a counter to gang, protected by ->i_rwsem of gang directory inode. * having it set to 1 at creation time, dropped in both spufs_dir_close() and spufs_gang_close() and bumped in spufs_create_context(), provided that it's not 0. * using simple_recursive_removal() to take the gang directory out when counter reaches zero.Show less

In the Linux kernel, the following vulnerability has been resolved: spufs: fix a leak in spufs_create_context() Leak fixes back in 2008 missed one case - if we are trying to set affinity and spufs_mkdir() fails, we need to drop the reference to neighbor.Show less

In the Linux kernel, the following vulnerability has been resolved: fs/9p: fix NULL pointer dereference on mkdir When a 9p tree was mounted with option 'posixacl', parent directory had a default ACL set for its subdirectories, e.g.: setfacl -m default:group:simpsons:rwx parentdir then creating a subdirectory crashed 9p client, as v9fs_fid_add() call in function v9fs_vfs_mkdir_dotl() sets the passed 'fid' pointer to NULL (since dafbe689736) even though the subsequent v9fs_set_create_acl() call expects a valid non-NULL 'fid' pointer: [ 37.273191] BUG: kernel NULL pointer dereference, address: 0000000000000000 ... [ 37.322338] Call Trace: [ 37.323043] <TASK> [ 37.323621] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 37.324448] ? page_fault_oops (arch/x86/mm/fault.c:714) [ 37.325532] ? search_module_extables (kernel/module/main.c:3733) [ 37.326742] ? p9_client_walk (net/9p/client.c:1165) 9pnet [ 37.328006] ? search_bpf_extables (kernel/bpf/core.c:804) [ 37.329142] ? exc_page_fault (./arch/x86/include/asm/paravirt.h:686 arch/x86/mm/fault.c:1488 arch/x86/mm/fault.c:1538) [ 37.330196] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:574) [ 37.331330] ? p9_client_walk (net/9p/client.c:1165) 9pnet [ 37.332562] ? v9fs_fid_xattr_get (fs/9p/xattr.c:30) 9p [ 37.333824] v9fs_fid_xattr_set (fs/9p/fid.h:23 fs/9p/xattr.c:121) 9p [ 37.335077] v9fs_set_acl (fs/9p/acl.c:276) 9p [ 37.336112] v9fs_set_create_acl (fs/9p/acl.c:307) 9p [ 37.337326] v9fs_vfs_mkdir_dotl (fs/9p/vfs_inode_dotl.c:411) 9p [ 37.338590] vfs_mkdir (fs/namei.c:4313) [ 37.339535] do_mkdirat (fs/namei.c:4336) [ 37.340465] __x64_sys_mkdir (fs/namei.c:4354) [ 37.341455] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) [ 37.342447] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Fix this by simply swapping the sequence of these two calls in v9fs_vfs_mkdir_dotl(), i.e. calling v9fs_set_create_acl() before v9fs_fid_add().Show less

In the Linux kernel, the following vulnerability has been resolved: riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler Naresh Kamboju reported a "Bad frame pointer" kernel warning while running LTP trace ftrace_stress_test.sh in riscv. We can reproduce the same issue with the following command: ``` $ cd /sys/kernel/debug/tracing $ echo 'f:myprobe do_nanosleep%return args1=$retval' > dynamic_events $ echo 1 > events/fprobes/enable $ echo 1 > tracing_on $ sleep 1 ``` And we can get the following kernel warning: [ 127.692888] ------------[ cut here ]------------ [ 127.693755] Bad frame pointer: expected ff2000000065be50, received ba34c141e9594000 [ 127.693755] from func do_nanosleep return to ffffffff800ccb16 [ 127.698699] WARNING: CPU: 1 PID: 129 at kernel/trace/fgraph.c:755 ftrace_return_to_handler+0x1b2/0x1be [ 127.699894] Modules linked in: [ 127.700908] CPU: 1 UID: 0 PID: 129 Comm: sleep Not tainted 6.14.0-rc3-g0ab191c74642 #32 [ 127.701453] Hardware name: riscv-virtio,qemu (DT) [ 127.701859] epc : ftrace_return_to_handler+0x1b2/0x1be [ 127.702032] ra : ftrace_return_to_handler+0x1b2/0x1be [ 127.702151] epc : ffffffff8013b5e0 ra : ffffffff8013b5e0 sp : ff2000000065bd10 [ 127.702221] gp : ffffffff819c12f8 tp : ff60000080853100 t0 : 6e00000000000000 [ 127.702284] t1 : 0000000000000020 t2 : 6e7566206d6f7266 s0 : ff2000000065bd80 [ 127.702346] s1 : ff60000081262000 a0 : 000000000000007b a1 : ffffffff81894f20 [ 127.702408] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 0000000000000000 [ 127.702470] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 [ 127.702530] s2 : ba34c141e9594000 s3 : 0000000000000000 s4 : ff2000000065bdd0 [ 127.702591] s5 : 00007fff8adcf400 s6 : 000055556dc1d8c0 s7 : 0000000000000068 [ 127.702651] s8 : 00007fff8adf5d10 s9 : 000000000000006d s10: 0000000000000001 [ 127.702710] s11: 00005555737377c8 t3 : ffffffff819d899e t4 : ffffffff819d899e [ 127.702769] t5 : ffffffff819d89a0 t6 : ff2000000065bb18 [ 127.702826] status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 127.703292] [<ffffffff8013b5e0>] ftrace_return_to_handler+0x1b2/0x1be [ 127.703760] [<ffffffff80017bce>] return_to_handler+0x16/0x26 [ 127.704009] [<ffffffff80017bb8>] return_to_handler+0x0/0x26 [ 127.704057] [<ffffffff800d3352>] common_nsleep+0x42/0x54 [ 127.704117] [<ffffffff800d44a2>] __riscv_sys_clock_nanosleep+0xba/0x10a [ 127.704176] [<ffffffff80901c56>] do_trap_ecall_u+0x188/0x218 [ 127.704295] [<ffffffff8090cc3e>] handle_exception+0x14a/0x156 [ 127.705436] ---[ end trace 0000000000000000 ]--- The reason is that the stack layout for constructing argument for the ftrace_return_to_handler in the return_to_handler does not match the __arch_ftrace_regs structure of riscv, leading to unexpected results.Show less

In the Linux kernel, the following vulnerability has been resolved: ublk: make sure ubq->canceling is set when queue is frozen Now ublk driver depends on `ubq->canceling` for deciding if the request can be dispatched via uring_cmd & io_uring_cmd_complete_in_task(). Once ubq->canceling is set, the uring_cmd can be done via ublk_cancel_cmd() and io_uring_cmd_done(). So set ubq->canceling when queue is frozen, this way makes sure that the flag can be observed from ublk_queue_rq() reliably, and avoids use-after-free on uring_cmd.Show less

In the Linux kernel, the following vulnerability has been resolved: spi: cadence: Fix out-of-bounds array access in cdns_mrvl_xspi_setup_clock() If requested_clk > 128, cdns_mrvl_xspi_setup_clock() iterates over the entire cdns_mrvl_xspi_clk_div_list array without breaking out early, causing 'i' to go beyond the array bounds. Fix that by stopping the loop when it gets to the last entry, clamping the clock to the minimum 6.25 MHz. Fixes the following warning with an UBSAN kernel: vmlinux.o: warning: objtool: cdns_mrvl_xspi_setup_clock: unexpected end of section .text.cdns_mrvl_xspi_setup_clockShow less

In the Linux kernel, the following vulnerability has been resolved: ASoC: imx-card: Add NULL check in imx_card_probe() devm_kasprintf() returns NULL when memory allocation fails. Currently, imx_card_probe() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue.Show less

In the Linux kernel, the following vulnerability has been resolved: idpf: fix adapter NULL pointer dereference on reboot With SRIOV enabled, idpf ends up calling into idpf_remove() twice. First via idpf_shutdown() and then again when idpf_remove() calls into sriov_disable(), because the VF devices use the idpf driver, hence the same remove routine. When that happens, it is possible for the adapter to be NULL from the first call to idpf_remove(), leading to a NULL pointer dereference. echo 1 > /sys/class/net/<netif>/device/sriov_numvfs reboot BUG: kernel NULL pointer dereference, address: 0000000000000020 ... RIP: 0010:idpf_remove+0x22/0x1f0 [idpf] ... ? idpf_remove+0x22/0x1f0 [idpf] ? idpf_remove+0x1e4/0x1f0 [idpf] pci_device_remove+0x3f/0xb0 device_release_driver_internal+0x19f/0x200 pci_stop_bus_device+0x6d/0x90 pci_stop_and_remove_bus_device+0x12/0x20 pci_iov_remove_virtfn+0xbe/0x120 sriov_disable+0x34/0xe0 idpf_sriov_configure+0x58/0x140 [idpf] idpf_remove+0x1b9/0x1f0 [idpf] idpf_shutdown+0x12/0x30 [idpf] pci_device_shutdown+0x35/0x60 device_shutdown+0x156/0x200 ... Replace the direct idpf_remove() call in idpf_shutdown() with idpf_vc_core_deinit() and idpf_deinit_dflt_mbx(), which perform the bulk of the cleanup, such as stopping the init task, freeing IRQs, destroying the vports and freeing the mailbox. This avoids the calls to sriov_disable() in addition to a small netdev cleanup, and destroying workqueues, which don't seem to be required on shutdown.Show less

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: don't unregister hook when table is dormant When nf_tables_updchain encounters an error, hook registration needs to be rolled back. This should only be done if the hook has been registered, which won't happen when the table is flagged as dormant (inactive). Just move the assignment into the registration block.Show less

In the Linux kernel, the following vulnerability has been resolved: netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets When calling netlbl_conn_setattr(), addr->sa_family is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipso_sock_setattr() is triggered. Inside this function, the following code is executed: sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL; Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference. This patch fixes the issue by checking if inet6_sk(sk) returns a NULL pointer before accessing pinet6.Show less

In the Linux kernel, the following vulnerability has been resolved: sctp: add mutual exclusion in proc_sctp_do_udp_port() We must serialize calls to sctp_udp_sock_stop() and sctp_udp_sock_start() or risk a crash as syzbot reported: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 1 UID: 0 PID: 6551 Comm: syz.1.44 Not tainted 6.14.0-syzkaller-g7f2ff7b62617 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:kernel_sock_shutdown+0x47/0x70 net/socket.c:3653 Call Trace: <TASK> udp_tunnel_sock_release+0x68/0x80 net/ipv4/udp_tunnel_core.c:181 sctp_udp_sock_stop+0x71/0x160 net/sctp/protocol.c:930 proc_sctp_do_udp_port+0x264/0x450 net/sctp/sysctl.c:553 proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0x91c/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xafd/0xe50 fs/read_write.c:1368 __do_sys_sendfile64 fs/read_write.c:1429 [inline] __se_sys_sendfile64 fs/read_write.c:1415 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1415 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]Show less

In the Linux kernel, the following vulnerability has been resolved: net: airoha: Fix qid report in airoha_tc_get_htb_get_leaf_queue() Fix the following kernel warning deleting HTB offloaded leafs and/or root HTB qdisc in airoha_eth driver properly reporting qid in airoha_tc_get_htb_get_leaf_queue routine. $tc qdisc replace dev eth1 root handle 10: htb offload $tc class add dev eth1 arent 10: classid 10:4 htb rate 100mbit ceil 100mbit $tc qdisc replace dev eth1 parent 10:4 handle 4: ets bands 8 \ quanta 1514 3028 4542 6056 7570 9084 10598 12112 $tc qdisc del dev eth1 root [ 55.827864] ------------[ cut here ]------------ [ 55.832493] WARNING: CPU: 3 PID: 2678 at 0xffffffc0798695a4 [ 55.956510] CPU: 3 PID: 2678 Comm: tc Tainted: G O 6.6.71 #0 [ 55.963557] Hardware name: Airoha AN7581 Evaluation Board (DT) [ 55.969383] pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 55.976344] pc : 0xffffffc0798695a4 [ 55.979851] lr : 0xffffffc079869a20 [ 55.983358] sp : ffffffc0850536a0 [ 55.986665] x29: ffffffc0850536a0 x28: 0000000000000024 x27: 0000000000000001 [ 55.993800] x26: 0000000000000000 x25: ffffff8008b19000 x24: ffffff800222e800 [ 56.000935] x23: 0000000000000001 x22: 0000000000000000 x21: ffffff8008b19000 [ 56.008071] x20: ffffff8002225800 x19: ffffff800379d000 x18: 0000000000000000 [ 56.015206] x17: ffffffbf9ea59000 x16: ffffffc080018000 x15: 0000000000000000 [ 56.022342] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000001 [ 56.029478] x11: ffffffc081471008 x10: ffffffc081575a98 x9 : 0000000000000000 [ 56.036614] x8 : ffffffc08167fd40 x7 : ffffffc08069e104 x6 : ffffff8007f86000 [ 56.043748] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000001 [ 56.050884] x2 : 0000000000000000 x1 : 0000000000000250 x0 : ffffff800222c000 [ 56.058020] Call trace: [ 56.060459] 0xffffffc0798695a4 [ 56.063618] 0xffffffc079869a20 [ 56.066777] __qdisc_destroy+0x40/0xa0 [ 56.070528] qdisc_put+0x54/0x6c [ 56.073748] qdisc_graft+0x41c/0x648 [ 56.077324] tc_get_qdisc+0x168/0x2f8 [ 56.080978] rtnetlink_rcv_msg+0x230/0x330 [ 56.085076] netlink_rcv_skb+0x5c/0x128 [ 56.088913] rtnetlink_rcv+0x14/0x1c [ 56.092490] netlink_unicast+0x1e0/0x2c8 [ 56.096413] netlink_sendmsg+0x198/0x3c8 [ 56.100337] ____sys_sendmsg+0x1c4/0x274 [ 56.104261] ___sys_sendmsg+0x7c/0xc0 [ 56.107924] __sys_sendmsg+0x44/0x98 [ 56.111492] __arm64_sys_sendmsg+0x20/0x28 [ 56.115580] invoke_syscall.constprop.0+0x58/0xfc [ 56.120285] do_el0_svc+0x3c/0xbc [ 56.123592] el0_svc+0x18/0x4c [ 56.126647] el0t_64_sync_handler+0x118/0x124 [ 56.131005] el0t_64_sync+0x150/0x154 [ 56.134660] ---[ end trace 0000000000000000 ]---Show less

In the Linux kernel, the following vulnerability has been resolved: net: mvpp2: Prevent parser TCAM memory corruption Protect the parser TCAM/SRAM memory, and the cached (shadow) SRAM information, from concurrent modifications. Both the TCAM and SRAM tables are indirectly accessed by configuring an index register that selects the row to read or write to. This means that operations must be atomic in order to, e.g., avoid spreading writes across multiple rows. Since the shadow SRAM array is used to find free rows in the hardware table, it must also be protected in order to avoid TOCTOU errors where multiple cores allocate the same row. This issue was detected in a situation where `mvpp2_set_rx_mode()` ran concurrently on two CPUs. In this particular case the MVPP2_PE_MAC_UC_PROMISCUOUS entry was corrupted, causing the classifier unit to drop all incoming unicast - indicated by the `rx_classifier_drops` counter.Show less

In the Linux kernel, the following vulnerability has been resolved: udp: Fix multiple wraparounds of sk->sk_rmem_alloc. __udp_enqueue_schedule_skb() has the following condition: if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) goto drop; sk->sk_rcvbuf is initialised by net.core.rmem_default and later can be configured by SO_RCVBUF, which is limited by net.core.rmem_max, or SO_RCVBUFFORCE. If we set INT_MAX to sk->sk_rcvbuf, the condition is always false as sk->sk_rmem_alloc is also signed int. Then, the size of the incoming skb is added to sk->sk_rmem_alloc unconditionally. This results in integer overflow (possibly multiple times) on sk->sk_rmem_alloc and allows a single socket to have skb up to net.core.udp_mem[1]. For example, if we set a large value to udp_mem[1] and INT_MAX to sk->sk_rcvbuf and flood packets to the socket, we can see multiple overflows: # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15 ^- PAGE_SHIFT # ss -uam State Recv-Q ... UNCONN -1757018048 ... <-- flipping the sign repeatedly skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0) Previously, we had a boundary check for INT_MAX, which was removed by commit 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc"). A complete fix would be to revert it and cap the right operand by INT_MAX: rmem = atomic_add_return(size, &sk->sk_rmem_alloc); if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX)) goto uncharge_drop; but we do not want to add the expensive atomic_add_return() back just for the corner case. Casting rmem to unsigned int prevents multiple wraparounds, but we still allow a single wraparound. # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> 12 # ss -uam State Recv-Q ... UNCONN -2147482816 ... <-- INT_MAX + 831 bytes skmem:(r2147484480,rb2147483646,t0,tb212992,f3264,w0,o0,bl0,d14468947) So, let's define rmem and rcvbuf as unsigned int and check skb->truesize only when rcvbuf is large enough to lower the overflow possibility. Note that we still have a small chance to see overflow if multiple skbs to the same socket are processed on different core at the same time and each size does not exceed the limit but the total size does. Note also that we must ignore skb->truesize for a small buffer as explained in commit 363dc73acacb ("udp: be less conservative with sock rmem accounting").Show less

In the Linux kernel, the following vulnerability has been resolved: udp: Fix memory accounting leak. Matt Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in /proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288 # python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common() purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory accounting. However, because the function takes a signed integer argument, the total size can wrap around, causing an overflow. Then, the released amount is calculated as follows: 1) Add size to sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480 (INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated"), memory usage no longer doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import * SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0)) s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM) c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data)Show less