An issue was discovered in the Linux kernel 3.16 through 5.5.6. set_fdc in drivers/block/floppy.c leads to a wait_til_ready out-of-bounds read because the FDC index is not checked for errors before assigning it, aka CID-2e90ca68b0d2.

In the Linux kernel, the following vulnerability has been resolved: rcu: Fix buffer overflow in print_cpu_stall_info() The rcuc-starvation output from print_cpu_stall_info() might overflow the buffer if there is a huge difference in jiffies difference. The situation might seem improbable, but computers sometimes get very confused about time, which can result in full-sized integers, and, in this case, buffer overflow. Also, the unsigned jiffies difference is printed using %ld, which is normally for signed integers. This is intentional for debugging purposes, but it is not obvious from the code. This commit therefore changes sprintf() to snprintf() and adds a clarifying comment about intention of %ld format. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: tty: serial: qcom-geni-serial: fix slab-out-of-bounds on RX FIFO buffer Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on default RX FIFO depth, e.g. 16. Later during serial startup the qcom_geni_serial_port_setup() updates the RX FIFO depth (port->rx_fifo_depth) to match real device capabilities, e.g. to 32. The RX UART handle code will read "port->rx_fifo_depth" number of words into "port->rx_fifo" buffer, thus exceeding the bounds. This can be observed in certain configurations with Qualcomm Bluetooth HCI UART device and KASAN: Bluetooth: hci0: QCA Product ID :0x00000010 Bluetooth: hci0: QCA SOC Version :0x400a0200 Bluetooth: hci0: QCA ROM Version :0x00000200 Bluetooth: hci0: QCA Patch Version:0x00000d2b Bluetooth: hci0: QCA controller version 0x02000200 Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2 Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2) Bluetooth: hci0: QCA Failed to download patch (-2) ================================================================== BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c Write of size 4 at addr ffff279347d578c0 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x8c/0xb8 print_report+0x188/0x488 kasan_report+0xb4/0x100 __asan_store4+0x80/0xa4 handle_rx_uart+0xa8/0x18c qcom_geni_serial_handle_rx+0x84/0x9c qcom_geni_serial_isr+0x24c/0x760 __handle_irq_event_percpu+0x108/0x500 handle_irq_event+0x6c/0x110 handle_fasteoi_irq+0x138/0x2cc generic_handle_domain_irq+0x48/0x64 If the RX FIFO depth changes after probe, be sure to resize the buffer.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on i_extra_isize in is_alive() syzbot found a f2fs bug: BUG: KASAN: slab-out-of-bounds in data_blkaddr fs/f2fs/f2fs.h:2891 [inline] BUG: KASAN: slab-out-of-bounds in is_alive fs/f2fs/gc.c:1117 [inline] BUG: KASAN: slab-out-of-bounds in gc_data_segment fs/f2fs/gc.c:1520 [inline] BUG: KASAN: slab-out-of-bounds in do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734 Read of size 4 at addr ffff888076557568 by task kworker/u4:3/52 CPU: 1 PID: 52 Comm: kworker/u4:3 Not tainted 6.1.0-rc4-syzkaller-00362-gfef7fd48922d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 data_blkaddr fs/f2fs/f2fs.h:2891 [inline] is_alive fs/f2fs/gc.c:1117 [inline] gc_data_segment fs/f2fs/gc.c:1520 [inline] do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734 f2fs_gc+0x88c/0x20a0 fs/f2fs/gc.c:1831 f2fs_balance_fs+0x544/0x6b0 fs/f2fs/segment.c:410 f2fs_write_inode+0x57e/0xe20 fs/f2fs/inode.c:753 write_inode fs/fs-writeback.c:1440 [inline] __writeback_single_inode+0xcfc/0x1440 fs/fs-writeback.c:1652 writeback_sb_inodes+0x54d/0xf90 fs/fs-writeback.c:1870 wb_writeback+0x2c5/0xd70 fs/fs-writeback.c:2044 wb_do_writeback fs/fs-writeback.c:2187 [inline] wb_workfn+0x2dc/0x12f0 fs/fs-writeback.c:2227 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The root cause is that we forgot to do sanity check on .i_extra_isize in below path, result in accessing invalid address later, fix it. - gc_data_segment - is_alive - data_blkaddr - offset_in_addr

An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11

The ATI Rage 128 (aka r128) driver in the Linux kernel before 2.6.31-git11 does not properly verify Concurrent Command Engine (CCE) state initialization, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly gain privileges via unspecified ioctl calls.

The Linux kernel 2.6.0 through 2.6.30.4, and 2.4.4 through 2.4.37.4, does not initialize all function pointers for socket operations in proto_ops structures, which allows local users to trigger a NULL pointer dereference and gain privileges by using mmap to map page zero, placing arbitrary code on this page, and then invoking an unavailable operation, as demonstrated by the sendpage operation (sock_sendpage function) on a PF_PPPOX socket.

In the Linux kernel, the following vulnerability has been resolved: dccp: fix dccp_v4_err()/dccp_v6_err() again dh->dccph_x is the 9th byte (offset 8) in "struct dccp_hdr", not in the "byte 7" as Jann claimed. We need to make sure the ICMP messages are big enough, using more standard ways (no more assumptions). syzbot reported: BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2681 [inline] BUG: KMSAN: uninit-value in dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] pskb_may_pull include/linux/skbuff.h:2681 [inline] dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 icmpv6_notify+0x4c7/0x880 net/ipv6/icmp.c:867 icmpv6_rcv+0x19d5/0x30d0 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:304 [inline] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x83b/0x920 tun_get_user+0x564c/0x6940 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6313 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1531 [inline] tun_get_user+0x23cf/0x6940 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 0 PID: 4995 Comm: syz-executor153 Not tainted 6.6.0-rc1-syzkaller-00014-ga747acc0b752 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023

In the Linux kernel, the following vulnerability has been resolved: net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg syzbot reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline] BUG: KMSAN: uninit-value in smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482 CPU: 0 PID: 8696 Comm: kworker/0:3 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline] smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482 usbnet_probe+0x1152/0x3f90 drivers/net/usb/usbnet.c:1737 usb_probe_interface+0xece/0x1550 drivers/usb/core/driver.c:374 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_set_configuration+0x380f/0x3f10 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:241 usb_probe_device+0x311/0x490 drivers/usb/core/driver.c:272 really_probe+0xf20/0x20b0 drivers/base/dd.c:529 driver_probe_device+0x293/0x390 drivers/base/dd.c:701 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554 hub_port_connect drivers/usb/core/hub.c:5208 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x5e7b/0x8a70 drivers/usb/core/hub.c:5576 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Local variable ----buf.i87@smsc75xx_bind created at: __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline] smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline] smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482 __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline] smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline] smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482 This issue is caused because usbnet_read_cmd() reads less bytes than requested (zero byte in the reproducer). In this case, 'buf' is not properly filled. This patch fixes the issue by returning -ENODATA if usbnet_read_cmd() reads less bytes than requested.

In the Linux kernel, the following vulnerability has been resolved: tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING syzbot reported the following uninit-value access issue [1]: ===================================================== BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline] BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756 strlen lib/string.c:418 [inline] strstr+0xb8/0x2f0 lib/string.c:756 tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595 genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595 __sys_sendmsg net/socket.c:2624 [inline] __do_sys_sendmsg net/socket.c:2633 [inline] __se_sys_sendmsg net/socket.c:2631 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd TIPC bearer-related names including link names must be null-terminated strings. If a link name which is not null-terminated is passed through netlink, strstr() and similar functions can cause buffer overrun. This causes the above issue. This patch changes the nla_policy for bearer-related names from NLA_STRING to NLA_NUL_STRING. This resolves the issue by ensuring that only null-terminated strings are accepted as bearer-related names. syzbot reported similar uninit-value issue related to bearer names [2]. The root cause of this issue is that a non-null-terminated bearer name was passed. This patch also resolved this issue.

An issue was discovered in fs/nfs/dir.c in the Linux kernel before 5.16.5. If an application sets the O_DIRECTORY flag, and tries to open a regular file, nfs_atomic_open() performs a regular lookup. If a regular file is found, ENOTDIR should occur, but the server instead returns uninitialized data in the file descriptor.

A kernel information leak flaw was identified in the scsi_ioctl function in drivers/scsi/scsi_ioctl.c in the Linux kernel. This flaw allows a local attacker with a special user privilege (CAP_SYS_ADMIN or CAP_SYS_RAWIO) to create issues with confidentiality.

A NULL pointer dereference flaw was found in the Linux kernel's BPF subsystem in the way a user triggers the map_get_next_key function of the BPF bloom filter. This flaw allows a local user to crash the system. This flaw affects Linux kernel versions prior to 5.17-rc1.

In the Linux kernel, the following vulnerability has been resolved: inet_diag: fix kernel-infoleak for UDP sockets KMSAN reported a kernel-infoleak [1], that can exploited by unpriv users. After analysis it turned out UDP was not initializing r->idiag_expires. Other users of inet_sk_diag_fill() might make the same mistake in the future, so fix this in inet_sk_diag_fill(). [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:156 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x69d/0x25c0 lib/iov_iter.c:670 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:156 [inline] _copy_to_iter+0x69d/0x25c0 lib/iov_iter.c:670 copy_to_iter include/linux/uio.h:155 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2cb/0x1280 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3657 [inline] netlink_recvmsg+0x660/0x1c60 net/netlink/af_netlink.c:1974 sock_recvmsg_nosec net/socket.c:944 [inline] sock_recvmsg net/socket.c:962 [inline] sock_read_iter+0x5a9/0x630 net/socket.c:1035 call_read_iter include/linux/fs.h:2156 [inline] new_sync_read fs/read_write.c:400 [inline] vfs_read+0x1631/0x1980 fs/read_write.c:481 ksys_read+0x28c/0x520 fs/read_write.c:619 __do_sys_read fs/read_write.c:629 [inline] __se_sys_read fs/read_write.c:627 [inline] __x64_sys_read+0xdb/0x120 fs/read_write.c:627 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:3251 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1126 [inline] netlink_dump+0x3d5/0x16a0 net/netlink/af_netlink.c:2245 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1343 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:276 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_write_iter+0x594/0x690 net/socket.c:1057 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x63f/0xe30 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 312 are uninitialized Memory access of size 312 starts at ffff88812ab54000 Data copied to user address 0000000020001440 CPU: 1 PID: 6365 Comm: syz-executor801 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-core: explicitly clear ioctl input data As seen from a recent syzbot bug report, mistakes in the compat ioctl implementation can lead to uninitialized kernel stack data getting used as input for driver ioctl handlers. The reported bug is now fixed, but it's possible that other related bugs are still present or get added in the future. As the drivers need to check user input already, the possible impact is fairly low, but it might still cause an information leak. To be on the safe side, always clear the entire ioctl buffer before calling the conversion handler functions that are meant to initialize them.

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - ADF_STATUS_PF_RUNNING should be set after adf_dev_init ADF_STATUS_PF_RUNNING is (only) used and checked by adf_vf2pf_shutdown() before calling adf_iov_putmsg()->mutex_lock(vf2pf_lock), however the vf2pf_lock is initialized in adf_dev_init(), which can fail and when it fail, the vf2pf_lock is either not initialized or destroyed, a subsequent use of vf2pf_lock will cause issue. To fix this issue, only set this flag if adf_dev_init() returns 0. [ 7.178404] BUG: KASAN: user-memory-access in __mutex_lock.isra.0+0x1ac/0x7c0 [ 7.180345] Call Trace: [ 7.182576] mutex_lock+0xc9/0xd0 [ 7.183257] adf_iov_putmsg+0x118/0x1a0 [intel_qat] [ 7.183541] adf_vf2pf_shutdown+0x4d/0x7b [intel_qat] [ 7.183834] adf_dev_shutdown+0x172/0x2b0 [intel_qat] [ 7.184127] adf_probe+0x5e9/0x600 [qat_dh895xccvf]

In the Linux kernel, the following vulnerability has been resolved: media: mxl111sf: change mutex_init() location Syzbot reported, that mxl111sf_ctrl_msg() uses uninitialized mutex. The problem was in wrong mutex_init() location. Previous mutex_init(&state->msg_lock) call was in ->init() function, but dvb_usbv2_init() has this order of calls: dvb_usbv2_init() dvb_usbv2_adapter_init() dvb_usbv2_adapter_frontend_init() props->frontend_attach() props->init() Since mxl111sf_* devices call mxl111sf_ctrl_msg() in ->frontend_attach() internally we need to initialize state->msg_lock before frontend_attach(). To achieve it, ->probe() call added to all mxl111sf_* devices, which will simply initiaize mutex.

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind() syzbot reported access to unitialized memory in mbind() [1] Issue came with commit bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") This commit added a new bit in MPOL_MODE_FLAGS, but only checked valid combination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in do_set_mempolicy() This patch moves the check in sanitize_mpol_flags() so that it is also used by mbind() [1] BUG: KMSAN: uninit-value in __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_alloc_node mm/slub.c:3221 [inline] slab_alloc mm/slub.c:3230 [inline] kmem_cache_alloc+0x751/0xff0 mm/slub.c:3235 mpol_new mm/mempolicy.c:293 [inline] do_mbind+0x912/0x15f0 mm/mempolicy.c:1289 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae ===================================================== Kernel panic - not syncing: panic_on_kmsan set ... CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G B 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106 dump_stack+0x25/0x28 lib/dump_stack.c:113 panic+0x44f/0xdeb kernel/panic.c:232 kmsan_report+0x2ee/0x300 mm/kmsan/report.c:186 __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:208 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: net: zero-initialize tc skb extension on allocation Function skb_ext_add() doesn't initialize created skb extension with any value and leaves it up to the user. However, since extension of type TC_SKB_EXT originally contained only single value tc_skb_ext->chain its users used to just assign the chain value without setting whole extension memory to zero first. This assumption changed when TC_SKB_EXT extension was extended with additional fields but not all users were updated to initialize the new fields which leads to use of uninitialized memory afterwards. UBSAN log: [ 778.299821] UBSAN: invalid-load in net/openvswitch/flow.c:899:28 [ 778.301495] load of value 107 is not a valid value for type '_Bool' [ 778.303215] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7+ #2 [ 778.304933] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 778.307901] Call Trace: [ 778.308680] <IRQ> [ 778.309358] dump_stack+0xbb/0x107 [ 778.310307] ubsan_epilogue+0x5/0x40 [ 778.311167] __ubsan_handle_load_invalid_value.cold+0x43/0x48 [ 778.312454] ? memset+0x20/0x40 [ 778.313230] ovs_flow_key_extract.cold+0xf/0x14 [openvswitch] [ 778.314532] ovs_vport_receive+0x19e/0x2e0 [openvswitch] [ 778.315749] ? ovs_vport_find_upcall_portid+0x330/0x330 [openvswitch] [ 778.317188] ? create_prof_cpu_mask+0x20/0x20 [ 778.318220] ? arch_stack_walk+0x82/0xf0 [ 778.319153] ? secondary_startup_64_no_verify+0xb0/0xbb [ 778.320399] ? stack_trace_save+0x91/0xc0 [ 778.321362] ? stack_trace_consume_entry+0x160/0x160 [ 778.322517] ? lock_release+0x52e/0x760 [ 778.323444] netdev_frame_hook+0x323/0x610 [openvswitch] [ 778.324668] ? ovs_netdev_get_vport+0xe0/0xe0 [openvswitch] [ 778.325950] __netif_receive_skb_core+0x771/0x2db0 [ 778.327067] ? lock_downgrade+0x6e0/0x6f0 [ 778.328021] ? lock_acquire+0x565/0x720 [ 778.328940] ? generic_xdp_tx+0x4f0/0x4f0 [ 778.329902] ? inet_gro_receive+0x2a7/0x10a0 [ 778.330914] ? lock_downgrade+0x6f0/0x6f0 [ 778.331867] ? udp4_gro_receive+0x4c4/0x13e0 [ 778.332876] ? lock_release+0x52e/0x760 [ 778.333808] ? dev_gro_receive+0xcc8/0x2380 [ 778.334810] ? lock_downgrade+0x6f0/0x6f0 [ 778.335769] __netif_receive_skb_list_core+0x295/0x820 [ 778.336955] ? process_backlog+0x780/0x780 [ 778.337941] ? mlx5e_rep_tc_netdevice_event_unregister+0x20/0x20 [mlx5_core] [ 778.339613] ? seqcount_lockdep_reader_access.constprop.0+0xa7/0xc0 [ 778.341033] ? kvm_clock_get_cycles+0x14/0x20 [ 778.342072] netif_receive_skb_list_internal+0x5f5/0xcb0 [ 778.343288] ? __kasan_kmalloc+0x7a/0x90 [ 778.344234] ? mlx5e_handle_rx_cqe_mpwrq+0x9e0/0x9e0 [mlx5_core] [ 778.345676] ? mlx5e_xmit_xdp_frame_mpwqe+0x14d0/0x14d0 [mlx5_core] [ 778.347140] ? __netif_receive_skb_list_core+0x820/0x820 [ 778.348351] ? mlx5e_post_rx_mpwqes+0xa6/0x25d0 [mlx5_core] [ 778.349688] ? napi_gro_flush+0x26c/0x3c0 [ 778.350641] napi_complete_done+0x188/0x6b0 [ 778.351627] mlx5e_napi_poll+0x373/0x1b80 [mlx5_core] [ 778.352853] __napi_poll+0x9f/0x510 [ 778.353704] ? mlx5_flow_namespace_set_mode+0x260/0x260 [mlx5_core] [ 778.355158] net_rx_action+0x34c/0xa40 [ 778.356060] ? napi_threaded_poll+0x3d0/0x3d0 [ 778.357083] ? sched_clock_cpu+0x18/0x190 [ 778.358041] ? __common_interrupt+0x8e/0x1a0 [ 778.359045] __do_softirq+0x1ce/0x984 [ 778.359938] __irq_exit_rcu+0x137/0x1d0 [ 778.360865] irq_exit_rcu+0xa/0x20 [ 778.361708] common_interrupt+0x80/0xa0 [ 778.362640] </IRQ> [ 778.363212] asm_common_interrupt+0x1e/0x40 [ 778.364204] RIP: 0010:native_safe_halt+0xe/0x10 [ 778.365273] Code: 4f ff ff ff 4c 89 e7 e8 50 3f 40 fe e9 dc fe ff ff 48 89 df e8 43 3f 40 fe eb 90 cc e9 07 00 00 00 0f 00 2d 74 05 62 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 64 05 62 00 f4 c3 cc cc 0f 1f 44 00 [ 778.369355] RSP: 0018:ffffffff84407e48 EFLAGS: 00000246 [ 778.370570] RAX ---truncated---

In the Linux kernel, the following vulnerability has been resolved: vdpa_sim: avoid putting an uninitialized iova_domain The system will crash if we put an uninitialized iova_domain, this could happen when an error occurs before initializing the iova_domain in vdpasim_create(). BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:__cpuhp_state_remove_instance+0x96/0x1c0 ... Call Trace: <TASK> put_iova_domain+0x29/0x220 vdpasim_free+0xd1/0x120 [vdpa_sim] vdpa_release_dev+0x21/0x40 [vdpa] device_release+0x33/0x90 kobject_release+0x63/0x160 vdpasim_create+0x127/0x2a0 [vdpa_sim] vdpasim_net_dev_add+0x7d/0xfe [vdpa_sim_net] vdpa_nl_cmd_dev_add_set_doit+0xe1/0x1a0 [vdpa] genl_family_rcv_msg_doit+0x112/0x140 genl_rcv_msg+0xdf/0x1d0 ... So we must make sure the iova_domain is already initialized before put it. In addition, we may get the following warning in this case: WARNING: ... drivers/iommu/iova.c:344 iova_cache_put+0x58/0x70 So we must make sure the iova_cache_put() is invoked only if the iova_cache_get() is already invoked. Let's fix it together.

Use of an uninitialized value in Skia in Google Chrome prior to 60.0.3112.78 for Mac, Windows, Linux, and Android allowed a remote attacker to obtain potentially sensitive information from process memory via a crafted HTML page.

An issue was discovered in romfs_dev_read in fs/romfs/storage.c in the Linux kernel before 5.8.4. Uninitialized memory leaks to userspace, aka CID-bcf85fcedfdd.

A flaw was found in vDPA with VDUSE backend. There are currently no checks in VDUSE kernel driver to ensure the size of the device config space is in line with the features advertised by the VDUSE userspace application. In case of a mismatch, Virtio drivers config read helpers do not initialize the memory indirectly passed to vduse_vdpa_get_config() returning uninitialized memory from the stack. This could cause undefined behavior or data leaks in Virtio drivers.

Opera before 9.52 on Windows, Linux, FreeBSD, and Solaris, when processing custom shortcut and menu commands, can produce argument strings that contain uninitialized memory, which might allow user-assisted remote attackers to execute arbitrary code or conduct other attacks via vectors related to activation of a shortcut.

In the Linux kernel, the following vulnerability has been resolved: net: hns3: put off calling register_netdev() until client initialize complete Currently, the netdevice is registered before client initializing complete. So there is a timewindow between netdevice available and usable. In this case, if user try to change the channel number or ring param, it may cause the hns3_set_rx_cpu_rmap() being called twice, and report bug. [47199.416502] hns3 0000:35:00.0 eth1: set channels: tqp_num=1, rxfh=0 [47199.430340] hns3 0000:35:00.0 eth1: already uninitialized [47199.438554] hns3 0000:35:00.0: rss changes from 4 to 1 [47199.511854] hns3 0000:35:00.0: Channels changed, rss_size from 4 to 1, tqps from 4 to 1 [47200.163524] ------------[ cut here ]------------ [47200.171674] kernel BUG at lib/cpu_rmap.c:142! [47200.177847] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [47200.185259] Modules linked in: hclge(+) hns3(-) hns3_cae(O) hns_roce_hw_v2 hnae3 vfio_iommu_type1 vfio_pci vfio_virqfd vfio pv680_mii(O) [last unloaded: hclge] [47200.205912] CPU: 1 PID: 8260 Comm: ethtool Tainted: G O 5.11.0-rc3+ #1 [47200.215601] Hardware name: , xxxxxx 02/04/2021 [47200.223052] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--) [47200.230188] pc : cpu_rmap_add+0x38/0x40 [47200.237472] lr : irq_cpu_rmap_add+0x84/0x140 [47200.243291] sp : ffff800010e93a30 [47200.247295] x29: ffff800010e93a30 x28: ffff082100584880 [47200.254155] x27: 0000000000000000 x26: 0000000000000000 [47200.260712] x25: 0000000000000000 x24: 0000000000000004 [47200.267241] x23: ffff08209ba03000 x22: ffff08209ba038c0 [47200.273789] x21: 000000000000003f x20: ffff0820e2bc1680 [47200.280400] x19: ffff0820c970ec80 x18: 00000000000000c0 [47200.286944] x17: 0000000000000000 x16: ffffb43debe4a0d0 [47200.293456] x15: fffffc2082990600 x14: dead000000000122 [47200.300059] x13: ffffffffffffffff x12: 000000000000003e [47200.306606] x11: ffff0820815b8080 x10: ffff53e411988000 [47200.313171] x9 : 0000000000000000 x8 : ffff0820e2bc1700 [47200.319682] x7 : 0000000000000000 x6 : 000000000000003f [47200.326170] x5 : 0000000000000040 x4 : ffff800010e93a20 [47200.332656] x3 : 0000000000000004 x2 : ffff0820c970ec80 [47200.339168] x1 : ffff0820e2bc1680 x0 : 0000000000000004 [47200.346058] Call trace: [47200.349324] cpu_rmap_add+0x38/0x40 [47200.354300] hns3_set_rx_cpu_rmap+0x6c/0xe0 [hns3] [47200.362294] hns3_reset_notify_init_enet+0x1cc/0x340 [hns3] [47200.370049] hns3_change_channels+0x40/0xb0 [hns3] [47200.376770] hns3_set_channels+0x12c/0x2a0 [hns3] [47200.383353] ethtool_set_channels+0x140/0x250 [47200.389772] dev_ethtool+0x714/0x23d0 [47200.394440] dev_ioctl+0x4cc/0x640 [47200.399277] sock_do_ioctl+0x100/0x2a0 [47200.404574] sock_ioctl+0x28c/0x470 [47200.409079] __arm64_sys_ioctl+0xb4/0x100 [47200.415217] el0_svc_common.constprop.0+0x84/0x210 [47200.422088] do_el0_svc+0x28/0x34 [47200.426387] el0_svc+0x28/0x70 [47200.431308] el0_sync_handler+0x1a4/0x1b0 [47200.436477] el0_sync+0x174/0x180 [47200.441562] Code: 11000405 79000c45 f8247861 d65f03c0 (d4210000) [47200.448869] ---[ end trace a01efe4ce42e5f34 ]--- The process is like below: excuting hns3_client_init | register_netdev() | hns3_set_channels() | | hns3_set_rx_cpu_rmap() hns3_reset_notify_uninit_enet() | | | quit without calling function | hns3_free_rx_cpu_rmap for flag | HNS3_NIC_STATE_INITED is unset. | | | hns3_reset_notify_init_enet() | | set HNS3_NIC_STATE_INITED call hns3_set_rx_cpu_rmap()-- crash Fix it by calling register_netdev() at the end of function hns3_client_init().

An issue was discovered in slc_bump in drivers/net/can/slcan.c in the Linux kernel 3.16 through 5.6.2. It allows attackers to read uninitialized can_frame data, potentially containing sensitive information from kernel stack memory, if the configuration lacks CONFIG_INIT_STACK_ALL, aka CID-b9258a2cece4.

A flaw was found in the Linux kernel's implementation of Userspace core dumps. This flaw allows an attacker with a local account to crash a trivial program and exfiltrate private kernel data.

In the Linux kernel, the following vulnerability has been resolved: ppp: Fix KMSAN uninit-value warning with bpf Syzbot caught an "KMSAN: uninit-value" warning [1], which is caused by the ppp driver not initializing a 2-byte header when using socket filter. The following code can generate a PPP filter BPF program: ''' struct bpf_program fp; pcap_t *handle; handle = pcap_open_dead(DLT_PPP_PPPD, 65535); pcap_compile(handle, &fp, "ip and outbound", 0, 0); bpf_dump(&fp, 1); ''' Its output is: ''' (000) ldh [2] (001) jeq #0x21 jt 2 jf 5 (002) ldb [0] (003) jeq #0x1 jt 4 jf 5 (004) ret #65535 (005) ret #0 ''' Wen can find similar code at the following link: https://github.com/ppp-project/ppp/blob/master/pppd/options.c#L1680 The maintainer of this code repository is also the original maintainer of the ppp driver. As you can see the BPF program skips 2 bytes of data and then reads the 'Protocol' field to determine if it's an IP packet. Then it read the first byte of the first 2 bytes to determine the direction. The issue is that only the first byte indicating direction is initialized in current ppp driver code while the second byte is not initialized. For normal BPF programs generated by libpcap, uninitialized data won't be used, so it's not a problem. However, for carefully crafted BPF programs, such as those generated by syzkaller [2], which start reading from offset 0, the uninitialized data will be used and caught by KMSAN. [1] https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791 [2] https://syzkaller.appspot.com/text?tag=ReproC&x=11994913980000

In the Linux kernel, the following vulnerability has been resolved: drop_monitor: fix incorrect initialization order Syzkaller reports the following bug: BUG: spinlock bad magic on CPU#1, syz-executor.0/7995 lock: 0xffff88805303f3e0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 1 PID: 7995 Comm: syz-executor.0 Tainted: G E 5.10.209+ #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x119/0x179 lib/dump_stack.c:118 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] do_raw_spin_lock+0x1f6/0x270 kernel/locking/spinlock_debug.c:112 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline] _raw_spin_lock_irqsave+0x50/0x70 kernel/locking/spinlock.c:159 reset_per_cpu_data+0xe6/0x240 [drop_monitor] net_dm_cmd_trace+0x43d/0x17a0 [drop_monitor] genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800 netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2497 genl_rcv+0x29/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x914/0xe00 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:651 [inline] __sock_sendmsg+0x157/0x190 net/socket.c:663 ____sys_sendmsg+0x712/0x870 net/socket.c:2378 ___sys_sendmsg+0xf8/0x170 net/socket.c:2432 __sys_sendmsg+0xea/0x1b0 net/socket.c:2461 do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f3f9815aee9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3f972bf0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3f9826d050 RCX: 00007f3f9815aee9 RDX: 0000000020000000 RSI: 0000000020001300 RDI: 0000000000000007 RBP: 00007f3f981b63bd R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f3f9826d050 R15: 00007ffe01ee6768 If drop_monitor is built as a kernel module, syzkaller may have time to send a netlink NET_DM_CMD_START message during the module loading. This will call the net_dm_monitor_start() function that uses a spinlock that has not yet been initialized. To fix this, let's place resource initialization above the registration of a generic netlink family. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree() Since commit b36e4523d4d5 ("netfilter: nf_conncount: fix garbage collection confirm race"), `cpu` and `jiffies32` were introduced to the struct nf_conncount_tuple. The commit made nf_conncount_add() initialize `conn->cpu` and `conn->jiffies32` when allocating the struct. In contrast, count_tree() was not changed to initialize them. By commit 34848d5c896e ("netfilter: nf_conncount: Split insert and traversal"), count_tree() was split and the relevant allocation code now resides in insert_tree(). Initialize `conn->cpu` and `conn->jiffies32` in insert_tree(). BUG: KMSAN: uninit-value in find_or_evict net/netfilter/nf_conncount.c:117 [inline] BUG: KMSAN: uninit-value in __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143 find_or_evict net/netfilter/nf_conncount.c:117 [inline] __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143 count_tree net/netfilter/nf_conncount.c:438 [inline] nf_conncount_count+0x82f/0x1e80 net/netfilter/nf_conncount.c:521 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72 __nft_match_eval net/netfilter/nft_compat.c:403 [inline] nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663 NF_HOOK_LIST include/linux/netfilter.h:350 [inline] ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:669 __netif_receive_skb_list_ptype net/core/dev.c:5936 [inline] __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5983 __netif_receive_skb_list net/core/dev.c:6035 [inline] netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:6126 netif_receive_skb_list+0x5a/0x460 net/core/dev.c:6178 xdp_recv_frames net/bpf/test_run.c:280 [inline] xdp_test_run_batch net/bpf/test_run.c:361 [inline] bpf_test_run_xdp_live+0x2e86/0x3480 net/bpf/test_run.c:390 bpf_prog_test_run_xdp+0xf1d/0x1ae0 net/bpf/test_run.c:1316 bpf_prog_test_run+0x5e5/0xa30 kernel/bpf/syscall.c:4407 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5813 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline] __se_sys_bpf kernel/bpf/syscall.c:5900 [inline] __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5900 ia32_sys_call+0x394d/0x4180 arch/x86/include/generated/asm/syscalls_32.h:358 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:412 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:450 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Uninit was created at: slab_post_alloc_hook mm/slub.c:4121 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x915/0xe10 mm/slub.c:4171 insert_tree net/netfilter/nf_conncount.c:372 [inline] count_tree net/netfilter/nf_conncount.c:450 [inline] nf_conncount_count+0x1415/0x1e80 net/netfilter/nf_conncount.c:521 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72 __nft_match_eval net/netfilter/nft_compat.c:403 [inline] nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663 NF_HOOK_LIST include/linux/netfilter.h:350 [inline] ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633 ip_list_rcv+0x9ef/0xa40 net/ip ---truncated---

In the Linux kernel, the following vulnerability has been resolved: arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL Currently tagged_addr_ctrl_set() doesn't initialize the temporary 'ctrl' variable, and a SETREGSET call with a length of zero will leave this uninitialized. Consequently tagged_addr_ctrl_set() will consume an arbitrary value, potentially leaking up to 64 bits of memory from the kernel stack. The read is limited to a specific slot on the stack, and the issue does not provide a write mechanism. As set_tagged_addr_ctrl() only accepts values where bits [63:4] zero and rejects other values, a partial SETREGSET attempt will randomly succeed or fail depending on the value of the uninitialized value, and the exposure is significantly limited. Fix this by initializing the temporary value before copying the regset from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG, NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing value of the tagged address ctrl will be retained. The NT_ARM_TAGGED_ADDR_CTRL regset is only visible in the user_aarch64_view used by a native AArch64 task to manipulate another native AArch64 task. As get_tagged_addr_ctrl() only returns an error value when called for a compat task, tagged_addr_ctrl_get() and tagged_addr_ctrl_set() should never observe an error value from get_tagged_addr_ctrl(). Add a WARN_ON_ONCE() to both to indicate that such an error would be unexpected, and error handlnig is not missing in either case.

In the Linux kernel through 5.4.6, there are information leaks of uninitialized memory to a USB device in the drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c driver, aka CID-da2311a6385c.

An issue was discovered in Ruby 2.5.x through 2.5.7, 2.6.x through 2.6.5, and 2.7.0. If a victim calls BasicSocket#read_nonblock(requested_size, buffer, exception: false), the method resizes the buffer to fit the requested size, but no data is copied. Thus, the buffer string provides the previous value of the heap. This may expose possibly sensitive data from the interpreter.

In the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_send_one(): fix missing CAN header initialization The read access to struct canxl_frame::len inside of a j1939 created skbuff revealed a missing initialization of reserved and later filled elements in struct can_frame. This patch initializes the 8 byte CAN header with zero.

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8712: fix uninit-value in r871xu_drv_init() When 'tmpU1b' returns from r8712_read8(padapter, EE_9346CR) is 0, 'mac[6]' will not be initialized. BUG: KMSAN: uninit-value in r871xu_drv_init+0x2d54/0x3070 drivers/staging/rtl8712/usb_intf.c:541 r871xu_drv_init+0x2d54/0x3070 drivers/staging/rtl8712/usb_intf.c:541 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396 really_probe+0x653/0x14b0 drivers/base/dd.c:596 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:752 driver_probe_device drivers/base/dd.c:782 [inline] __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:899 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427 __device_attach+0x593/0x8e0 drivers/base/dd.c:970 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1017 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487 device_add+0x1fff/0x26e0 drivers/base/core.c:3405 usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238 usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293 really_probe+0x653/0x14b0 drivers/base/dd.c:596 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:752 driver_probe_device drivers/base/dd.c:782 [inline] __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:899 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427 __device_attach+0x593/0x8e0 drivers/base/dd.c:970 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1017 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487 device_add+0x1fff/0x26e0 drivers/base/core.c:3405 usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2566 hub_port_connect drivers/usb/core/hub.c:5358 [inline] hub_port_connect_change drivers/usb/core/hub.c:5502 [inline] port_event drivers/usb/core/hub.c:5660 [inline] hub_event+0x58e3/0x89e0 drivers/usb/core/hub.c:5742 process_one_work+0xdb6/0x1820 kernel/workqueue.c:2307 worker_thread+0x10b3/0x21e0 kernel/workqueue.c:2454 kthread+0x3c7/0x500 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 Local variable mac created at: r871xu_drv_init+0x1771/0x3070 drivers/staging/rtl8712/usb_intf.c:394 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396 KMSAN: uninit-value in r871xu_drv_init https://syzkaller.appspot.com/bug?id=3cd92b1d85428b128503bfa7a250294c9ae00bd8

In the Linux kernel, the following vulnerability has been resolved: tipc: check attribute length for bearer name syzbot reported uninit-value: ===================================================== BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:644 [inline] BUG: KMSAN: uninit-value in string+0x4f9/0x6f0 lib/vsprintf.c:725 string_nocheck lib/vsprintf.c:644 [inline] string+0x4f9/0x6f0 lib/vsprintf.c:725 vsnprintf+0x2222/0x3650 lib/vsprintf.c:2806 vprintk_store+0x537/0x2150 kernel/printk/printk.c:2158 vprintk_emit+0x28b/0xab0 kernel/printk/printk.c:2256 vprintk_default+0x86/0xa0 kernel/printk/printk.c:2283 vprintk+0x15f/0x180 kernel/printk/printk_safe.c:50 _printk+0x18d/0x1cf kernel/printk/printk.c:2293 tipc_enable_bearer net/tipc/bearer.c:371 [inline] __tipc_nl_bearer_enable+0x2022/0x22a0 net/tipc/bearer.c:1033 tipc_nl_bearer_enable+0x6c/0xb0 net/tipc/bearer.c:1042 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] - Do sanity check the attribute length for TIPC_NLA_BEARER_NAME. - Do not use 'illegal name' in printing message.

In the Linux kernel, the following vulnerability has been resolved: igb: Initialize mailbox message for VF reset When a MAC address is not assigned to the VF, that portion of the message sent to the VF is not set. The memory, however, is allocated from the stack meaning that information may be leaked to the VM. Initialize the message buffer to 0 so that no information is passed to the VM in this case.

In the Linux kernel, the following vulnerability has been resolved: vdpa/mlx5: add validation for VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command When control vq receives a VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command request from the driver, presently there is no validation against the number of queue pairs to configure, or even if multiqueue had been negotiated or not is unverified. This may lead to kernel panic due to uninitialized resource for the queues were there any bogus request sent down by untrusted driver. Tie up the loose ends there.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix possible bogus match in nf_osf_find() nf_osf_find() incorrectly returns true on mismatch, this leads to copying uninitialized memory area in nft_osf which can be used to leak stale kernel stack data to userspace.

In the Linux kernel before 5.2.9, there is an info-leak bug that can be caused by a malicious USB device in the drivers/net/can/usb/peak_usb/pcan_usb_fd.c driver, aka CID-30a8beeb3042.

In the Linux kernel through 5.3.8, f->fmt.sdr.reserved is uninitialized in rcar_drif_g_fmt_sdr_cap in drivers/media/platform/rcar_drif.c, which could cause a memory disclosure problem.

In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed.

In the Linux kernel, the following vulnerability has been resolved: tipc: fix the msg->req tlv len check in tipc_nl_compat_name_table_dump_header This is a follow-up for commit 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") where it should have type casted sizeof(..) to int to work when TLV_GET_DATA_LEN() returns a negative value. syzbot reported a call trace because of it: BUG: KMSAN: uninit-value in ... tipc_nl_compat_name_table_dump+0x841/0xea0 net/tipc/netlink_compat.c:934 __tipc_nl_compat_dumpit+0xab2/0x1320 net/tipc/netlink_compat.c:238 tipc_nl_compat_dumpit+0x991/0xb50 net/tipc/netlink_compat.c:321 tipc_nl_compat_recv+0xb6e/0x1640 net/tipc/netlink_compat.c:1324 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x103f/0x1260 net/netlink/genetlink.c:792 netlink_rcv_skb+0x3a5/0x6c0 net/netlink/af_netlink.c:2501 genl_rcv+0x3c/0x50 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline]

In the Linux kernel, the following vulnerability has been resolved: regulator: da9121: Fix uninit-value in da9121_assign_chip_model() KASAN report slab-out-of-bounds in __regmap_init as follows: BUG: KASAN: slab-out-of-bounds in __regmap_init drivers/base/regmap/regmap.c:841 Read of size 1 at addr ffff88803678cdf1 by task xrun/9137 CPU: 0 PID: 9137 Comm: xrun Tainted: G W 5.18.0-rc2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0xe8/0x15a lib/dump_stack.c:88 print_report.cold+0xcd/0x69b mm/kasan/report.c:313 kasan_report+0x8e/0xc0 mm/kasan/report.c:491 __regmap_init+0x4540/0x4ba0 drivers/base/regmap/regmap.c:841 __devm_regmap_init+0x7a/0x100 drivers/base/regmap/regmap.c:1266 __devm_regmap_init_i2c+0x65/0x80 drivers/base/regmap/regmap-i2c.c:394 da9121_i2c_probe+0x386/0x6d1 drivers/regulator/da9121-regulator.c:1039 i2c_device_probe+0x959/0xac0 drivers/i2c/i2c-core-base.c:563 This happend when da9121 device is probe by da9121_i2c_id, but with invalid dts. Thus, chip->subvariant_id is set to -EINVAL, and later da9121_assign_chip_model() will access 'regmap' without init it. Fix it by return -EINVAL from da9121_assign_chip_model() if 'chip->subvariant_id' is invalid.

In the Linux kernel, the following vulnerability has been resolved: rtl818x: Prevent using not initialized queues Using not existing queues can panic the kernel with rtl8180/rtl8185 cards. Ignore the skb priority for those cards, they only have one tx queue. Pierre Asselin (pa@panix.com) reported the kernel crash in the Gentoo forum: https://forums.gentoo.org/viewtopic-t-1147832-postdays-0-postorder-asc-start-25.html He also confirmed that this patch fixes the issue. In summary this happened: After updating wpa_supplicant from 2.9 to 2.10 the kernel crashed with a "divide error: 0000" when connecting to an AP. Control port tx now tries to use IEEE80211_AC_VO for the priority, which wpa_supplicants starts to use in 2.10. Since only the rtl8187se part of the driver supports QoS, the priority of the skb is set to IEEE80211_AC_BE (2) by mac80211 for rtl8180/rtl8185 cards. rtl8180 is then unconditionally reading out the priority and finally crashes on drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c line 544 without this patch: idx = (ring->idx + skb_queue_len(&ring->queue)) % ring->entries "ring->entries" is zero for rtl8180/rtl8185 cards, tx_ring[2] never got initialized.

Use of an uninitialized value in Skia in Google Chrome prior to 60.0.3112.78 for Linux, Windows, and Mac allowed a remote attacker to obtain potentially sensitive information from process memory via a crafted HTML page.

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8712: fix uninit-value in usb_read8() and friends When r8712_usbctrl_vendorreq() returns negative, 'data' in usb_read{8,16,32} will not be initialized. BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:643 [inline] BUG: KMSAN: uninit-value in string+0x4ec/0x6f0 lib/vsprintf.c:725 string_nocheck lib/vsprintf.c:643 [inline] string+0x4ec/0x6f0 lib/vsprintf.c:725 vsnprintf+0x2222/0x3650 lib/vsprintf.c:2806 va_format lib/vsprintf.c:1704 [inline] pointer+0x18e6/0x1f70 lib/vsprintf.c:2443 vsnprintf+0x1a9b/0x3650 lib/vsprintf.c:2810 vprintk_store+0x537/0x2150 kernel/printk/printk.c:2158 vprintk_emit+0x28b/0xab0 kernel/printk/printk.c:2256 dev_vprintk_emit+0x5ef/0x6d0 drivers/base/core.c:4604 dev_printk_emit+0x1dd/0x21f drivers/base/core.c:4615 __dev_printk+0x3be/0x440 drivers/base/core.c:4627 _dev_info+0x1ea/0x22f drivers/base/core.c:4673 r871xu_drv_init+0x1929/0x3070 drivers/staging/rtl8712/usb_intf.c:401 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396 really_probe+0x6c7/0x1350 drivers/base/dd.c:621 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:752 driver_probe_device drivers/base/dd.c:782 [inline] __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:899 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427 __device_attach+0x593/0x8e0 drivers/base/dd.c:970 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1017 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487 device_add+0x1fff/0x26e0 drivers/base/core.c:3405 usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238 usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293 really_probe+0x6c7/0x1350 drivers/base/dd.c:621 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:752 driver_probe_device drivers/base/dd.c:782 [inline] __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:899 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427 __device_attach+0x593/0x8e0 drivers/base/dd.c:970 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1017 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487 device_add+0x1fff/0x26e0 drivers/base/core.c:3405 usb_new_device+0x1b91/0x2950 drivers/usb/core/hub.c:2566 hub_port_connect drivers/usb/core/hub.c:5363 [inline] hub_port_connect_change drivers/usb/core/hub.c:5507 [inline] port_event drivers/usb/core/hub.c:5665 [inline] hub_event+0x58e3/0x89e0 drivers/usb/core/hub.c:5747 process_one_work+0xdb6/0x1820 kernel/workqueue.c:2289 worker_thread+0x10d0/0x2240 kernel/workqueue.c:2436 kthread+0x3c7/0x500 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 Local variable data created at: usb_read8+0x5d/0x130 drivers/staging/rtl8712/usb_ops.c:33 r8712_read8+0xa5/0xd0 drivers/staging/rtl8712/rtl8712_io.c:29 KMSAN: uninit-value in r871xu_drv_init https://syzkaller.appspot.com/bug?id=3cd92b1d85428b128503bfa7a250294c9ae00bd8

In the Linux kernel, the following vulnerability has been resolved: net: nexthop: Initialize all fields in dumped nexthops struct nexthop_grp contains two reserved fields that are not initialized by nla_put_nh_group(), and carry garbage. This can be observed e.g. with strace (edited for clarity): # ip nexthop add id 1 dev lo # ip nexthop add id 101 group 1 # strace -e recvmsg ip nexthop get id 101 ... recvmsg(... [{nla_len=12, nla_type=NHA_GROUP}, [{id=1, weight=0, resvd1=0x69, resvd2=0x67}]] ...) = 52 The fields are reserved and therefore not currently used. But as they are, they leak kernel memory, and the fact they are not just zero complicates repurposing of the fields for new ends. Initialize the full structure.

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix uninit-value in mpol_rebind_policy() mpol_set_nodemask()(mm/mempolicy.c) does not set up nodemask when pol->mode is MPOL_LOCAL. Check pol->mode before access pol->w.cpuset_mems_allowed in mpol_rebind_policy()(mm/mempolicy.c). BUG: KMSAN: uninit-value in mpol_rebind_policy mm/mempolicy.c:352 [inline] BUG: KMSAN: uninit-value in mpol_rebind_task+0x2ac/0x2c0 mm/mempolicy.c:368 mpol_rebind_policy mm/mempolicy.c:352 [inline] mpol_rebind_task+0x2ac/0x2c0 mm/mempolicy.c:368 cpuset_change_task_nodemask kernel/cgroup/cpuset.c:1711 [inline] cpuset_attach+0x787/0x15e0 kernel/cgroup/cpuset.c:2278 cgroup_migrate_execute+0x1023/0x1d20 kernel/cgroup/cgroup.c:2515 cgroup_migrate kernel/cgroup/cgroup.c:2771 [inline] cgroup_attach_task+0x540/0x8b0 kernel/cgroup/cgroup.c:2804 __cgroup1_procs_write+0x5cc/0x7a0 kernel/cgroup/cgroup-v1.c:520 cgroup1_tasks_write+0x94/0xb0 kernel/cgroup/cgroup-v1.c:539 cgroup_file_write+0x4c2/0x9e0 kernel/cgroup/cgroup.c:3852 kernfs_fop_write_iter+0x66a/0x9f0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x1318/0x2030 fs/read_write.c:590 ksys_write+0x28b/0x510 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:3251 [inline] slab_alloc mm/slub.c:3259 [inline] kmem_cache_alloc+0x902/0x11c0 mm/slub.c:3264 mpol_new mm/mempolicy.c:293 [inline] do_set_mempolicy+0x421/0xb70 mm/mempolicy.c:853 kernel_set_mempolicy mm/mempolicy.c:1504 [inline] __do_sys_set_mempolicy mm/mempolicy.c:1510 [inline] __se_sys_set_mempolicy+0x44c/0xb60 mm/mempolicy.c:1507 __x64_sys_set_mempolicy+0xd8/0x110 mm/mempolicy.c:1507 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae KMSAN: uninit-value in mpol_rebind_task (2) https://syzkaller.appspot.com/bug?id=d6eb90f952c2a5de9ea718a1b873c55cb13b59dc This patch seems to fix below bug too. KMSAN: uninit-value in mpol_rebind_mm (2) https://syzkaller.appspot.com/bug?id=f2fecd0d7013f54ec4162f60743a2b28df40926b The uninit-value is pol->w.cpuset_mems_allowed in mpol_rebind_policy(). When syzkaller reproducer runs to the beginning of mpol_new(), mpol_new() mm/mempolicy.c do_mbind() mm/mempolicy.c kernel_mbind() mm/mempolicy.c `mode` is 1(MPOL_PREFERRED), nodes_empty(*nodes) is `true` and `flags` is 0. Then mode = MPOL_LOCAL; ... policy->mode = mode; policy->flags = flags; will be executed. So in mpol_set_nodemask(), mpol_set_nodemask() mm/mempolicy.c do_mbind() kernel_mbind() pol->mode is 4 (MPOL_LOCAL), that `nodemask` in `pol` is not initialized, which will be accessed in mpol_rebind_policy().

In the Linux kernel, the following vulnerability has been resolved: nbd: always initialize struct msghdr completely syzbot complains that msg->msg_get_inq value can be uninitialized [1] struct msghdr got many new fields recently, we should always make sure their values is zero by default. [1] BUG: KMSAN: uninit-value in tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 inet_recvmsg+0x131/0x580 net/ipv4/af_inet.c:879 sock_recvmsg_nosec net/socket.c:1044 [inline] sock_recvmsg+0x12b/0x1e0 net/socket.c:1066 __sock_xmit+0x236/0x5c0 drivers/block/nbd.c:538 nbd_read_reply drivers/block/nbd.c:732 [inline] recv_work+0x262/0x3100 drivers/block/nbd.c:863 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700 worker_thread+0xf45/0x1490 kernel/workqueue.c:2781 kthread+0x3ed/0x540 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Local variable msg created at: __sock_xmit+0x4c/0x5c0 drivers/block/nbd.c:513 nbd_read_reply drivers/block/nbd.c:732 [inline] recv_work+0x262/0x3100 drivers/block/nbd.c:863 CPU: 1 PID: 7465 Comm: kworker/u5:1 Not tainted 6.7.0-rc7-syzkaller-00041-gf016f7547aee #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: nbd5-recv recv_work