CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-46787 – userfaultfd: fix checks for huge PMDs
https://notcve.org/view.php?id=CVE-2024-46787
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix checks for huge PMDs Patch series "userfaultfd: fix races around pmd_trans_huge() check", v2. The pmd_trans_huge() code in mfill_atomic() is wrong in three different ways depending on kernel version: 1. The pmd_trans_huge() check is racy and can lead to a BUG_ON() (if you hit the right two race windows) - I've tested this in a kernel build with some extra mdelay() calls. See the commit message for a description of the race scenario. On older kernels (before 6.5), I think the same bug can even theoretically lead to accessing transhuge page contents as a page table if you hit the right 5 narrow race windows (I haven't tested this case). 2. As pointed out by Qi Zheng, pmd_trans_huge() is not sufficient for detecting PMDs that don't point to page tables. On older kernels (before 6.5), you'd just have to win a single fairly wide race to hit this. I've tested this on 6.1 stable by racing migration (with a mdelay() patched into try_to_migrate()) against UFFDIO_ZEROPAGE - on my x86 VM, that causes a kernel oops in ptlock_ptr(). 3. On newer kernels (>=6.5), for shmem mappings, khugepaged is allowed to yank page tables out from under us (though I haven't tested that), so I think the BUG_ON() checks in mfill_atomic() are just wrong. I decided to write two separate fixes for these (one fix for bugs 1+2, one fix for bug 3), so that the first fix can be backported to kernels affected by bugs 1+2. This patch (of 2): This fixes two issues. I discovered that the following race can occur: mfill_atomic other thread ============ ============ <zap PMD> pmdp_get_lockless() [reads none pmd] <bail if trans_huge> <if none:> <pagefault creates transhuge zeropage> __pte_alloc [no-op] <zap PMD> <bail if pmd_trans_huge(*dst_pmd)> BUG_ON(pmd_none(*dst_pmd)) I have experimentally verified this in a kernel with extra mdelay() calls; the BUG_ON(pmd_none(*dst_pmd)) triggers. On kernels newer than commit 0d940a9b270b ("mm/pgtable: allow pte_offset_map[_lock]() to fail"), this can't lead to anything worse than a BUG_ON(), since the page table access helpers are actually designed to deal with page tables concurrently disappearing; but on older kernels (<=6.4), I think we could probably theoretically race past the two BUG_ON() checks and end up treating a hugepage as a page table. The second issue is that, as Qi Zheng pointed out, there are other types of huge PMDs that pmd_trans_huge() can't catch: devmap PMDs and swap PMDs (in particular, migration PMDs). On <=6.4, this is worse than the first issue: If mfill_atomic() runs on a PMD that contains a migration entry (which just requires winning a single, fairly wide race), it will pass the PMD to pte_offset_map_lock(), which assumes that the PMD points to a page table. Breakage follows: First, the kernel tries to take the PTE lock (which will crash or maybe worse if there is no "struct page" for the address bits in the migration entry PMD - I think at least on X86 there usually is no corresponding "struct page" thanks to the PTE inversion mitigation, amd64 looks different). If that didn't crash, the kernel would next try to write a PTE into what it wrongly thinks is a page table. As part of fixing these issues, get rid of the check for pmd_trans_huge() before __pte_alloc() - that's redundant, we're going to have to check for that after the __pte_alloc() anyway. Backport note: pmdp_get_lockless() is pmd_read_atomic() in older kernels. • https://git.kernel.org/stable/c/c1a4de99fada21e2e9251e52cbb51eff5aadc757 https://git.kernel.org/stable/c/3c6b4bcf37845c9359aed926324bed66bdd2448d https://git.kernel.org/stable/c/98cc18b1b71e23fe81a5194ed432b20c2d81a01a https://git.kernel.org/stable/c/71c186efc1b2cf1aeabfeff3b9bd5ac4c5ac14d8 •
CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2024-46786 – fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF
https://notcve.org/view.php?id=CVE-2024-46786
In the Linux kernel, the following vulnerability has been resolved: fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF The fscache_cookie_lru_timer is initialized when the fscache module is inserted, but is not deleted when the fscache module is removed. If timer_reduce() is called before removing the fscache module, the fscache_cookie_lru_timer will be added to the timer list of the current cpu. Afterwards, a use-after-free will be triggered in the softIRQ after removing the fscache module, as follows: ================================================================== BUG: unable to handle page fault for address: fffffbfff803c9e9 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855 Tainted: [W]=WARN RIP: 0010:__run_timer_base.part.0+0x254/0x8a0 Call Trace: <IRQ> tmigr_handle_remote_up+0x627/0x810 __walk_groups.isra.0+0x47/0x140 tmigr_handle_remote+0x1fa/0x2f0 handle_softirqs+0x180/0x590 irq_exit_rcu+0x84/0xb0 sysvec_apic_timer_interrupt+0x6e/0x90 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:default_idle+0xf/0x20 default_idle_call+0x38/0x60 do_idle+0x2b5/0x300 cpu_startup_entry+0x54/0x60 start_secondary+0x20d/0x280 common_startup_64+0x13e/0x148 </TASK> Modules linked in: [last unloaded: netfs] ================================================================== Therefore delete fscache_cookie_lru_timer when removing the fscahe module. • https://git.kernel.org/stable/c/12bb21a29c19aae50cfad4e2bb5c943108f34a7d https://git.kernel.org/stable/c/e0d724932ad12e3528f4ce97fc0f6078d0cce4bc https://git.kernel.org/stable/c/0a11262549ac2ac6fb98c7cd40a67136817e5a52 https://git.kernel.org/stable/c/72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f •
CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2024-46784 – net: mana: Fix error handling in mana_create_txq/rxq's NAPI cleanup
https://notcve.org/view.php?id=CVE-2024-46784
In the Linux kernel, the following vulnerability has been resolved: net: mana: Fix error handling in mana_create_txq/rxq's NAPI cleanup Currently napi_disable() gets called during rxq and txq cleanup, even before napi is enabled and hrtimer is initialized. It causes kernel panic. ? page_fault_oops+0x136/0x2b0 ? page_counter_cancel+0x2e/0x80 ? do_user_addr_fault+0x2f2/0x640 ? • https://git.kernel.org/stable/c/e1b5683ff62e7b328317aec08869495992053e9d https://git.kernel.org/stable/c/9178eb8ebcd887ab75e54ac40d538e54bb9c7788 https://git.kernel.org/stable/c/9e0bff4900b5d412a9bafe4baeaa6facd34f671c https://git.kernel.org/stable/c/4982a47154f0b50de81ee0a0b169a3fc74120a65 https://git.kernel.org/stable/c/b6ecc662037694488bfff7c9fd21c405df8411f2 •
CVSS: -EPSS: 0%CPEs: 7EXPL: 0CVE-2024-46783 – tcp_bpf: fix return value of tcp_bpf_sendmsg()
https://notcve.org/view.php?id=CVE-2024-46783
In the Linux kernel, the following vulnerability has been resolved: tcp_bpf: fix return value of tcp_bpf_sendmsg() When we cork messages in psock->cork, the last message triggers the flushing will result in sending a sk_msg larger than the current message size. In this case, in tcp_bpf_send_verdict(), 'copied' becomes negative at least in the following case: 468 case __SK_DROP: 469 default: 470 sk_msg_free_partial(sk, msg, tosend); 471 sk_msg_apply_bytes(psock, tosend); 472 *copied -= (tosend + delta); // <==== HERE 473 return -EACCES; Therefore, it could lead to the following BUG with a proper value of 'copied' (thanks to syzbot). We should not use negative 'copied' as a return value here. ------------[ cut here ]------------ kernel BUG at net/socket.c:733! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 3265 Comm: syz-executor510 Not tainted 6.11.0-rc3-syzkaller-00060-gd07b43284ab3 #0 Hardware name: linux,dummy-virt (DT) pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : sock_sendmsg_nosec net/socket.c:733 [inline] pc : sock_sendmsg_nosec net/socket.c:728 [inline] pc : __sock_sendmsg+0x5c/0x60 net/socket.c:745 lr : sock_sendmsg_nosec net/socket.c:730 [inline] lr : __sock_sendmsg+0x54/0x60 net/socket.c:745 sp : ffff800088ea3b30 x29: ffff800088ea3b30 x28: fbf00000062bc900 x27: 0000000000000000 x26: ffff800088ea3bc0 x25: ffff800088ea3bc0 x24: 0000000000000000 x23: f9f00000048dc000 x22: 0000000000000000 x21: ffff800088ea3d90 x20: f9f00000048dc000 x19: ffff800088ea3d90 x18: 0000000000000001 x17: 0000000000000000 x16: 0000000000000000 x15: 000000002002ffaf x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: ffff8000815849c0 x9 : ffff8000815b49c0 x8 : 0000000000000000 x7 : 000000000000003f x6 : 0000000000000000 x5 : 00000000000007e0 x4 : fff07ffffd239000 x3 : fbf00000062bc900 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00000000fffffdef Call trace: sock_sendmsg_nosec net/socket.c:733 [inline] __sock_sendmsg+0x5c/0x60 net/socket.c:745 ____sys_sendmsg+0x274/0x2ac net/socket.c:2597 ___sys_sendmsg+0xac/0x100 net/socket.c:2651 __sys_sendmsg+0x84/0xe0 net/socket.c:2680 __do_sys_sendmsg net/socket.c:2689 [inline] __se_sys_sendmsg net/socket.c:2687 [inline] __arm64_sys_sendmsg+0x24/0x30 net/socket.c:2687 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151 el0_svc+0x34/0xec arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598 Code: f9404463 d63f0060 3108441f 54fffe81 (d4210000) ---[ end trace 0000000000000000 ]--- • https://git.kernel.org/stable/c/4f738adba30a7cfc006f605707e7aee847ffefa0 https://git.kernel.org/stable/c/6f9fdf5806cced888c43512bccbdf7fefd50f510 https://git.kernel.org/stable/c/3efe53eb221a38e207c1e3f81c51e4ca057d50c2 https://git.kernel.org/stable/c/78bb38d9c5a311c5f8bdef7c9557d7d81ca30e4a https://git.kernel.org/stable/c/810a4e7d92dea4074cb04c25758320909d752193 https://git.kernel.org/stable/c/c8219a27fa43a2cbf99f5176f6dddfe73e7a24ae https://git.kernel.org/stable/c/126d72b726c4cf1119f3a7fe413a78d341c3fea9 https://git.kernel.org/stable/c/fe1910f9337bd46a9343967b547ccab26 •
CVSS: -EPSS: 0%CPEs: 8EXPL: 0CVE-2024-46782 – ila: call nf_unregister_net_hooks() sooner
https://notcve.org/view.php?id=CVE-2024-46782
In the Linux kernel, the following vulnerability has been resolved: ila: call nf_unregister_net_hooks() sooner syzbot found an use-after-free Read in ila_nf_input [1] Issue here is that ila_xlat_exit_net() frees the rhashtable, then call nf_unregister_net_hooks(). It should be done in the reverse way, with a synchronize_rcu(). This is a good match for a pre_exit() method. [1] BUG: KASAN: use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline] BUG: KASAN: use-after-free in __rhashtable_lookup include/linux/rhashtable.h:604 [inline] BUG: KASAN: use-after-free in rhashtable_lookup include/linux/rhashtable.h:646 [inline] BUG: KASAN: use-after-free in rhashtable_lookup_fast+0x77a/0x9b0 include/linux/rhashtable.h:672 Read of size 4 at addr ffff888064620008 by task ksoftirqd/0/16 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.11.0-rc4-syzkaller-00238-g2ad6d23f465a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 rht_key_hashfn include/linux/rhashtable.h:159 [inline] __rhashtable_lookup include/linux/rhashtable.h:604 [inline] rhashtable_lookup include/linux/rhashtable.h:646 [inline] rhashtable_lookup_fast+0x77a/0x9b0 include/linux/rhashtable.h:672 ila_lookup_wildcards net/ipv6/ila/ila_xlat.c:132 [inline] ila_xlat_addr net/ipv6/ila/ila_xlat.c:652 [inline] ila_nf_input+0x1fe/0x3c0 net/ipv6/ila/ila_xlat.c:190 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcb/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x64620 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xbfffffff(buddy) raw: 00fff00000000000 ffffea0000959608 ffffea00019d9408 0000000000000000 raw: 0000000000000000 0000000000000003 00000000bfffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO), pid 5242, tgid 5242 (syz-executor), ts 73611328570, free_ts 618981657187 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] ___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4103 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4130 __do_kmalloc_node mm/slub.c:4146 [inline] __kmalloc_node_noprof+0x2d2/0x440 mm/slub.c:4164 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:650 bucket_table_alloc lib/rhashtable.c:186 [inline] rhashtable_init_noprof+0x534/0xa60 lib/rhashtable.c:1071 ila_xlat_init_net+0xa0/0x110 net/ipv6/ila/ila_xlat.c:613 ops_ini ---truncated--- • https://git.kernel.org/stable/c/7f00feaf107645d95a6d87e99b4d141ac0a08efd https://git.kernel.org/stable/c/43d34110882b97ba1ec66cc8234b18983efb9abf https://git.kernel.org/stable/c/dcaf4e2216824839d26727a15b638c6a677bd9fc https://git.kernel.org/stable/c/93ee345ba349922834e6a9d1dadabaedcc12dce6 https://git.kernel.org/stable/c/bda4d84ac0d5421b346faee720011f58bdb99673 https://git.kernel.org/stable/c/925c18a7cff93d8a4320d652351294ff7d0ac93c https://git.kernel.org/stable/c/18a5a16940464b301ea91bf5da3a324aedb347b2 https://git.kernel.org/stable/c/47abd8adddbc0aecb8f231269ef659148 •