Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: HID: amd_sfh: Fix potential NULL pointer dereference devm_add_action_or_reset() can suddenly invoke amd_mp2_pci_remove() at registration that will cause NULL pointer dereference since corresponding data is not initialized yet. The patch moves initialization of data before devm_add_action_or_reset(). Found by Linux Driver Verification project (linuxtesting.org). [jkosina@suse.cz: rebase]Show less

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd KASAN reports a use-after-free report when doing fuzz test: [693354.104835] ================================================================== [693354.105094] BUG: KASAN: use-after-free in bfq_io_set_weight_legacy+0xd3/0x160 [693354.105336] Read of size 4 at addr ffff888be0a35664 by task sh/1453338 [693354.105607] CPU: 41 PID: 1453338 Comm: sh Kdump: loaded Not tainted 4.18.0-147 [693354.105610] Hardware name: Huawei 2288H V5/BC11SPSCB0, BIOS 0.81 07/02/2018 [693354.105612] Call Trace: [693354.105621] dump_stack+0xf1/0x19b [693354.105626] ? show_regs_print_info+0x5/0x5 [693354.105634] ? printk+0x9c/0xc3 [693354.105638] ? cpumask_weight+0x1f/0x1f [693354.105648] print_address_description+0x70/0x360 [693354.105654] kasan_report+0x1b2/0x330 [693354.105659] ? bfq_io_set_weight_legacy+0xd3/0x160 [693354.105665] ? bfq_io_set_weight_legacy+0xd3/0x160 [693354.105670] bfq_io_set_weight_legacy+0xd3/0x160 [693354.105675] ? bfq_cpd_init+0x20/0x20 [693354.105683] cgroup_file_write+0x3aa/0x510 [693354.105693] ? ___slab_alloc+0x507/0x540 [693354.105698] ? cgroup_file_poll+0x60/0x60 [693354.105702] ? 0xffffffff89600000 [693354.105708] ? usercopy_abort+0x90/0x90 [693354.105716] ? mutex_lock+0xef/0x180 [693354.105726] kernfs_fop_write+0x1ab/0x280 [693354.105732] ? cgroup_file_poll+0x60/0x60 [693354.105738] vfs_write+0xe7/0x230 [693354.105744] ksys_write+0xb0/0x140 [693354.105749] ? __ia32_sys_read+0x50/0x50 [693354.105760] do_syscall_64+0x112/0x370 [693354.105766] ? syscall_return_slowpath+0x260/0x260 [693354.105772] ? do_page_fault+0x9b/0x270 [693354.105779] ? prepare_exit_to_usermode+0xf9/0x1a0 [693354.105784] ? enter_from_user_mode+0x30/0x30 [693354.105793] entry_SYSCALL_64_after_hwframe+0x65/0xca [693354.105875] Allocated by task 1453337: [693354.106001] kasan_kmalloc+0xa0/0xd0 [693354.106006] kmem_cache_alloc_node_trace+0x108/0x220 [693354.106010] bfq_pd_alloc+0x96/0x120 [693354.106015] blkcg_activate_policy+0x1b7/0x2b0 [693354.106020] bfq_create_group_hierarchy+0x1e/0x80 [693354.106026] bfq_init_queue+0x678/0x8c0 [693354.106031] blk_mq_init_sched+0x1f8/0x460 [693354.106037] elevator_switch_mq+0xe1/0x240 [693354.106041] elevator_switch+0x25/0x40 [693354.106045] elv_iosched_store+0x1a1/0x230 [693354.106049] queue_attr_store+0x78/0xb0 [693354.106053] kernfs_fop_write+0x1ab/0x280 [693354.106056] vfs_write+0xe7/0x230 [693354.106060] ksys_write+0xb0/0x140 [693354.106064] do_syscall_64+0x112/0x370 [693354.106069] entry_SYSCALL_64_after_hwframe+0x65/0xca [693354.106114] Freed by task 1453336: [693354.106225] __kasan_slab_free+0x130/0x180 [693354.106229] kfree+0x90/0x1b0 [693354.106233] blkcg_deactivate_policy+0x12c/0x220 [693354.106238] bfq_exit_queue+0xf5/0x110 [693354.106241] blk_mq_exit_sched+0x104/0x130 [693354.106245] __elevator_exit+0x45/0x60 [693354.106249] elevator_switch_mq+0xd6/0x240 [693354.106253] elevator_switch+0x25/0x40 [693354.106257] elv_iosched_store+0x1a1/0x230 [693354.106261] queue_attr_store+0x78/0xb0 [693354.106264] kernfs_fop_write+0x1ab/0x280 [693354.106268] vfs_write+0xe7/0x230 [693354.106271] ksys_write+0xb0/0x140 [693354.106275] do_syscall_64+0x112/0x370 [693354.106280] entry_SYSCALL_64_after_hwframe+0x65/0xca [693354.106329] The buggy address belongs to the object at ffff888be0a35580 which belongs to the cache kmalloc-1k of size 1024 [693354.106736] The buggy address is located 228 bytes inside of 1024-byte region [ffff888be0a35580, ffff888be0a35980) [693354.107114] The buggy address belongs to the page: [693354.107273] page:ffffea002f828c00 count:1 mapcount:0 mapping:ffff888107c17080 index:0x0 compound_mapcount: 0 [693354.107606] flags: 0x17ffffc0008100(slab|head) [693354.107760] raw: 0017ffffc0008100 ffffea002fcbc808 ffffea0030bd3a08 ffff888107c17080 [693354.108020] r ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: nvme-rdma: destroy cm id before destroy qp to avoid use after free We should always destroy cm_id before destroy qp to avoid to get cma event after qp was destroyed, which may lead to use after free. In RDMA connection establishment error flow, don't destroy qp in cm event handler.Just report cm_error to upper level, qp will be destroy in nvme_rdma_alloc_queue() after destroy cm id.Show less

In the Linux kernel, the following vulnerability has been resolved: bpf: Add oversize check before call kvcalloc() Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the oversize check. When the allocation is larger than what kmalloc() supports, the following warning triggered: WARNING: CPU: 0 PID: 8408 at mm/util.c:597 kvmalloc_node+0x108/0x110 mm/util.c:597 Modules linked in: CPU: 0 PID: 8408 Comm: syz-executor221 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvmalloc_node+0x108/0x110 mm/util.c:597 Call Trace: kvmalloc include/linux/mm.h:806 [inline] kvmalloc_array include/linux/mm.h:824 [inline] kvcalloc include/linux/mm.h:829 [inline] check_btf_line kernel/bpf/verifier.c:9925 [inline] check_btf_info kernel/bpf/verifier.c:10049 [inline] bpf_check+0xd634/0x150d0 kernel/bpf/verifier.c:13759 bpf_prog_load kernel/bpf/syscall.c:2301 [inline] __sys_bpf+0x11181/0x126e0 kernel/bpf/syscall.c:4587 __do_sys_bpf kernel/bpf/syscall.c:4691 [inline] __se_sys_bpf kernel/bpf/syscall.c:4689 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4689 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xaeShow less

In the Linux kernel, the following vulnerability has been resolved: blktrace: Fix uaf in blk_trace access after removing by sysfs There is an use-after-free problem triggered by following process: P1(sda) P2(sdb) echo 0 > /sys/block/sdb/trace/enable blk_trace_remove_queue synchronize_rcu blk_trace_free relay_close rcu_read_lock __blk_add_trace trace_note_tsk (Iterate running_trace_list) relay_close_buf relay_destroy_buf kfree(buf) trace_note(sdb's bt) relay_reserve buf->offset <- nullptr deference (use-after-free) !!! rcu_read_unlock [ 502.714379] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 502.715260] #PF: supervisor read access in kernel mode [ 502.715903] #PF: error_code(0x0000) - not-present page [ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0 [ 502.717252] Oops: 0000 [#1] SMP [ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360 [ 502.732872] Call Trace: [ 502.733193] __blk_add_trace.cold+0x137/0x1a3 [ 502.733734] blk_add_trace_rq+0x7b/0xd0 [ 502.734207] blk_add_trace_rq_issue+0x54/0xa0 [ 502.734755] blk_mq_start_request+0xde/0x1b0 [ 502.735287] scsi_queue_rq+0x528/0x1140 ... [ 502.742704] sg_new_write.isra.0+0x16e/0x3e0 [ 502.747501] sg_ioctl+0x466/0x1100 Reproduce method: ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sda, BLKTRACESTART) ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sdb, BLKTRACESTART) echo 0 > /sys/block/sdb/trace/enable & // Add delay(mdelay/msleep) before kernel enters blk_trace_free() ioctl$SG_IO(/dev/sda, SG_IO, ...) // Enters trace_note_tsk() after blk_trace_free() returned // Use mdelay in rcu region rather than msleep(which may schedule out) Remove blk_trace from running_list before calling blk_trace_free() by sysfs if blk_trace is at Blktrace_running state.Show less

In the Linux kernel, the following vulnerability has been resolved: dma-debug: prevent an error message from causing runtime problems For some drivers, that use the DMA API. This error message can be reached several millions of times per second, causing spam to the kernel's printk buffer and bringing the CPU usage up to 100% (so, it should be rate limited). However, since there is at least one driver that is in the mainline and suffers from the error condition, it is more useful to err_printk() here instead of just rate limiting the error message (in hopes that it will make it easier for other drivers that suffer from this issue to be spotted).Show less

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Fix potential VPE leak on error In its_vpe_irq_domain_alloc, when its_vpe_init() returns an error, there is an off-by-one in the number of VPEs to be freed. Fix it by simply passing the number of VPEs allocated, which is the index of the loop iterating over the VPEs. [maz: fixed commit message]Show less

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix use after free on rmmod plat_dev->dev->platform_data is released by platform_device_unregister(), use of pclk and hclk is a use-after-free. Since device unregister won't need a clk device we adjust the function call sequence to fix this issue. [ 31.261225] BUG: KASAN: use-after-free in macb_remove+0x77/0xc6 [macb_pci] [ 31.275563] Freed by task 306: [ 30.276782] platform_device_release+0x25/0x80Show less

In the Linux kernel, the following vulnerability has been resolved: nexthop: Fix memory leaks in nexthop notification chain listeners syzkaller discovered memory leaks [1] that can be reduced to the following commands: # ip nexthop add id 1 blackhole # devlink dev reload pci/0000:06:00.0 As part of the reload flow, mlxsw will unregister its netdevs and then unregister from the nexthop notification chain. Before unregistering from the notification chain, mlxsw will receive delete notifications for nexthop objects using netdevs registered by mlxsw or their uppers. mlxsw will not receive notifications for nexthops using netdevs that are not dismantled as part of the reload flow. For example, the blackhole nexthop above that internally uses the loopback netdev as its nexthop device. One way to fix this problem is to have listeners flush their nexthop tables after unregistering from the notification chain. This is error-prone as evident by this patch and also not symmetric with the registration path where a listener receives a dump of all the existing nexthops. Therefore, fix this problem by replaying delete notifications for the listener being unregistered. This is symmetric to the registration path and also consistent with the netdev notification chain. The above means that unregister_nexthop_notifier(), like register_nexthop_notifier(), will have to take RTNL in order to iterate over the existing nexthops and that any callers of the function cannot hold RTNL. This is true for mlxsw and netdevsim, but not for the VXLAN driver. To avoid a deadlock, change the latter to unregister its nexthop listener without holding RTNL, making it symmetric to the registration path. [1] unreferenced object 0xffff88806173d600 (size 512): comm "syz-executor.0", pid 1290, jiffies 4295583142 (age 143.507s) hex dump (first 32 bytes): 41 9d 1e 60 80 88 ff ff 08 d6 73 61 80 88 ff ff A..`......sa.... 08 d6 73 61 80 88 ff ff 01 00 00 00 00 00 00 00 ..sa............ backtrace: [<ffffffff81a6b576>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<ffffffff81a6b576>] slab_post_alloc_hook+0x96/0x490 mm/slab.h:522 [<ffffffff81a716d3>] slab_alloc_node mm/slub.c:3206 [inline] [<ffffffff81a716d3>] slab_alloc mm/slub.c:3214 [inline] [<ffffffff81a716d3>] kmem_cache_alloc_trace+0x163/0x370 mm/slub.c:3231 [<ffffffff82e8681a>] kmalloc include/linux/slab.h:591 [inline] [<ffffffff82e8681a>] kzalloc include/linux/slab.h:721 [inline] [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_group_create drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:4918 [inline] [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_new drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5054 [inline] [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_event+0x59a/0x2910 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5239 [<ffffffff813ef67d>] notifier_call_chain+0xbd/0x210 kernel/notifier.c:83 [<ffffffff813f0662>] blocking_notifier_call_chain kernel/notifier.c:318 [inline] [<ffffffff813f0662>] blocking_notifier_call_chain+0x72/0xa0 kernel/notifier.c:306 [<ffffffff8384b9c6>] call_nexthop_notifiers+0x156/0x310 net/ipv4/nexthop.c:244 [<ffffffff83852bd8>] insert_nexthop net/ipv4/nexthop.c:2336 [inline] [<ffffffff83852bd8>] nexthop_add net/ipv4/nexthop.c:2644 [inline] [<ffffffff83852bd8>] rtm_new_nexthop+0x14e8/0x4d10 net/ipv4/nexthop.c:2913 [<ffffffff833e9a78>] rtnetlink_rcv_msg+0x448/0xbf0 net/core/rtnetlink.c:5572 [<ffffffff83608703>] netlink_rcv_skb+0x173/0x480 net/netlink/af_netlink.c:2504 [<ffffffff833de032>] rtnetlink_rcv+0x22/0x30 net/core/rtnetlink.c:5590 [<ffffffff836069de>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] [<ffffffff836069de>] netlink_unicast+0x5ae/0x7f0 net/netlink/af_netlink.c:1340 [<ffffffff83607501>] netlink_sendmsg+0x8e1/0xe30 net/netlink/af_netlink.c:1929 [<ffffffff832fde84>] sock_sendmsg_nosec net/socket.c:704 [inline ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: mptcp: ensure tx skbs always have the MPTCP ext Due to signed/unsigned comparison, the expression: info->size_goal - skb->len > 0 evaluates to true when the size goal is smaller than the skb size. That results in lack of tx cache refill, so that the skb allocated by the core TCP code lacks the required MPTCP skb extensions. Due to the above, syzbot is able to trigger the following WARN_ON(): WARNING: CPU: 1 PID: 810 at net/mptcp/protocol.c:1366 mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Modules linked in: CPU: 1 PID: 810 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366 Code: ff 4c 8b 74 24 50 48 8b 5c 24 58 e9 0f fb ff ff e8 13 44 8b f8 4c 89 e7 45 31 ed e8 98 57 2e fe e9 81 f4 ff ff e8 fe 43 8b f8 <0f> 0b 41 bd ea ff ff ff e9 6f f4 ff ff 4c 89 e7 e8 b9 8e d2 f8 e9 RSP: 0018:ffffc9000531f6a0 EFLAGS: 00010216 RAX: 000000000000697f RBX: 0000000000000000 RCX: ffffc90012107000 RDX: 0000000000040000 RSI: ffffffff88eac9e2 RDI: 0000000000000003 RBP: ffff888078b15780 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88eac017 R11: 0000000000000000 R12: ffff88801de0a280 R13: 0000000000006b58 R14: ffff888066278280 R15: ffff88803c2fe9c0 FS: 00007fd9f866e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faebcb2f718 CR3: 00000000267cb000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mptcp_push_pending+0x1fb/0x6b0 net/mptcp/protocol.c:1547 mptcp_release_cb+0xfe/0x210 net/mptcp/protocol.c:3003 release_sock+0xb4/0x1b0 net/core/sock.c:3206 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145 mptcp_sendmsg+0xc39/0x1bc0 net/mptcp/protocol.c:1749 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:643 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x2a0/0x3e0 net/socket.c:1057 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x40b/0x640 fs/read_write.c:507 vfs_write+0x7cf/0xae0 fs/read_write.c:594 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd9f866e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 00000000000e7b78 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 0000000000a9fb1f R14: 00007fd9f866e300 R15: 0000000000022000 Fix the issue rewriting the relevant expression to avoid sign-related problems - note: size_goal is always >= 0. Additionally, ensure that the skb in the tx cache always carries the relevant extension.Show less

In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix NULL deref in qeth_clear_working_pool_list() When qeth_set_online() calls qeth_clear_working_pool_list() to roll back after an error exit from qeth_hardsetup_card(), we are at risk of accessing card->qdio.in_q before it was allocated by qeth_alloc_qdio_queues() via qeth_mpc_initialize(). qeth_clear_working_pool_list() then dereferences NULL, and by writing to queue->bufs[i].pool_entry scribbles all over the CPU's lowcore. Resulting in a crash when those lowcore areas are used next (eg. on the next machine-check interrupt). Such a scenario would typically happen when the device is first set online and its queues aren't allocated yet. An early IO error or certain misconfigs (eg. mismatched transport mode, bad portno) then cause us to error out from qeth_hardsetup_card() with card->qdio.in_q still being NULL. Fix it by checking the pointer for NULL before accessing it. Note that we also have (rare) paths inside qeth_mpc_initialize() where a configuration change can cause us to free the existing queues, expecting that subsequent code will allocate them again. If we then error out before that re-allocation happens, the same bug occurs. Root-caused-by: Heiko Carstens <hca@linux.ibm.com>Show less

In the Linux kernel, the following vulnerability has been resolved: enetc: Fix illegal access when reading affinity_hint irq_set_affinity_hit() stores a reference to the cpumask_t parameter in the irq descriptor, and that reference can be accessed later from irq_affinity_hint_proc_show(). Since the cpu_mask parameter passed to irq_set_affinity_hit() has only temporary storage (it's on the stack memory), later accesses to it are illegal. Thus reads from the corresponding procfs affinity_hint file can result in paging request oops. The issue is fixed by the get_cpu_mask() helper, which provides a permanent storage for the cpumask_t parameter.Show less

In the Linux kernel, the following vulnerability has been resolved: virtio-net: fix pages leaking when building skb in big mode We try to use build_skb() if we had sufficient tailroom. But we forget to release the unused pages chained via private in big mode which will leak pages. Fixing this by release the pages after building the skb in big mode.Show less

In the Linux kernel, the following vulnerability has been resolved: afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and Linux's afs client switches between them when talking to a non-YFS server if the read size, the file position or the sum of the two have the upper 32 bits set of the 64-bit value. This is a problem, however, since the file position and length fields of FS.FetchData are *signed* 32-bit values. Fix this by capturing the capability bits obtained from the fileserver when it's sent an FS.GetCapabilities RPC, rather than just discarding them, and then picking out the VICED_CAPABILITY_64BITFILES flag. This can then be used to decide whether to use FS.FetchData or FS.FetchData64 - and also FS.StoreData or FS.StoreData64 - rather than using upper_32_bits() to switch on the parameter values. This capabilities flag could also be used to limit the maximum size of the file, but all servers must be checked for that. Note that the issue does not exist with FS.StoreData - that uses *unsigned* 32-bit values. It's also not a problem with Auristor servers as its YFS.FetchData64 op uses unsigned 64-bit values. This can be tested by cloning a git repo through an OpenAFS client to an OpenAFS server and then doing "git status" on it from a Linux afs client[1]. Provided the clone has a pack file that's in the 2G-4G range, the git status will show errors like: error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index This can be observed in the server's FileLog with something like the following appearing: Sun Aug 29 19:31:39 2021 SRXAFS_FetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001 Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: Pos 18446744071815340032, Len 3154 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: file size 2400758866 ... Sun Aug 29 19:31:40 2021 SRXAFS_FetchData returns 5 Note the file position of 18446744071815340032. This is the requested file position sign-extended.Show less

In the Linux kernel, the following vulnerability has been resolved: afs: Fix page leak There's a loop in afs_extend_writeback() that adds extra pages to a write we want to make to improve the efficiency of the writeback by making it larger. This loop stops, however, if we hit a page we can't write back from immediately, but it doesn't get rid of the page ref we speculatively acquired. This was caused by the removal of the cleanup loop when the code switched from using find_get_pages_contig() to xarray scanning as the latter only gets a single page at a time, not a batch. Fix this by putting the page on a ref on an early break from the loop. Unfortunately, we can't just add that page to the pagevec we're employing as we'll go through that and add those pages to the RPC call. This was found by the generic/074 test. It leaks ~4GiB of RAM each time it is run - which can be observed with "top".Show less

In the Linux kernel, the following vulnerability has been resolved: comedi: Fix memory leak in compat_insnlist() `compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST` ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to temporarily hold an array of `struct comedi_insn` converted from the 32-bit version in user space. This memory is only being freed if there is a fault while filling the array, otherwise it is leaked. Add a call to `kfree()` to fix the leak.Show less

In the Linux kernel, the following vulnerability has been resolved: nexthop: Fix division by zero while replacing a resilient group The resilient nexthop group torture tests in fib_nexthop.sh exposed a possible division by zero while replacing a resilient group [1]. The division by zero occurs when the data path sees a resilient nexthop group with zero buckets. The tests replace a resilient nexthop group in a loop while traffic is forwarded through it. The tests do not specify the number of buckets while performing the replacement, resulting in the kernel allocating a stub resilient table (i.e, 'struct nh_res_table') with zero buckets. This table should never be visible to the data path, but the old nexthop group (i.e., 'oldg') might still be used by the data path when the stub table is assigned to it. Fix this by only assigning the stub table to the old nexthop group after making sure the group is no longer used by the data path. Tested with fib_nexthops.sh: Tests passed: 222 Tests failed: 0 [1] divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014 RIP: 0010:nexthop_select_path+0x2d2/0x1a80 [...] Call Trace: fib_select_multipath+0x79b/0x1530 fib_select_path+0x8fb/0x1c10 ip_route_output_key_hash_rcu+0x1198/0x2da0 ip_route_output_key_hash+0x190/0x340 ip_route_output_flow+0x21/0x120 raw_sendmsg+0x91d/0x2e10 inet_sendmsg+0x9e/0xe0 __sys_sendto+0x23d/0x360 __x64_sys_sendto+0xe1/0x1b0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xaeShow less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Update intermediate power state for SI Update the current state as boot state during dpm initialization. During the subsequent initialization, set_power_state gets called to transition to the final power state. set_power_state refers to values from the current state and without current state populated, it could result in NULL pointer dereference. For ex: on platforms where PCI speed change is supported through ACPI ATCS method, the link speed of current state needs to be queried before deciding on changing to final power state's link speed. The logic to query ATCS-support was broken on certain platforms. The issue became visible when broken ATCS-support logic got fixed with commit f9b7f3703ff9 ("drm/amdgpu/acpi: make ATPX/ATCS structures global (v2)"). Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1698Show less

In the Linux kernel, the following vulnerability has been resolved: mcb: fix error handling in mcb_alloc_bus() There are two bugs: 1) If ida_simple_get() fails then this code calls put_device(carrier) but we haven't yet called get_device(carrier) and probably that leads to a use after free. 2) After device_initialize() then we need to use put_device() to release the bus. This will free the internal resources tied to the device and call mcb_free_bus() which will free the rest.Show less