CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2024-46794 – x86/tdx: Fix data leak in mmio_read()
https://notcve.org/view.php?id=CVE-2024-46794
In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix data leak in mmio_read() The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an address from the VMM. Sean noticed that mmio_read() unintentionally exposes the value of an initialized variable (val) on the stack to the VMM. This variable is only needed as an output value. It did not need to be passed to the VMM in the first place. Do not send the original value of *val to the VMM. [ dhansen: clarify what 'val' is used for. ] • https://git.kernel.org/stable/c/31d58c4e557d46fa7f8557714250fb6f89c941ae https://git.kernel.org/stable/c/26c6af49d26ffc377e392e30d4086db19eed0ef7 https://git.kernel.org/stable/c/ef00818c50cf55a3a56bd9a9fae867c92dfb84e7 https://git.kernel.org/stable/c/b55ce742afcb8e8189d82f2f1e635ba1b5a461fa https://git.kernel.org/stable/c/b6fb565a2d15277896583d471b21bc14a0c99661 •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2024-46791 – can: mcp251x: fix deadlock if an interrupt occurs during mcp251x_open
https://notcve.org/view.php?id=CVE-2024-46791
In the Linux kernel, the following vulnerability has been resolved: can: mcp251x: fix deadlock if an interrupt occurs during mcp251x_open The mcp251x_hw_wake() function is called with the mpc_lock mutex held and disables the interrupt handler so that no interrupts can be processed while waking the device. If an interrupt has already occurred then waiting for the interrupt handler to complete will deadlock because it will be trying to acquire the same mutex. CPU0 CPU1 ---- ---- mcp251x_open() mutex_lock(&priv->mcp_lock) request_threaded_irq() <interrupt> mcp251x_can_ist() mutex_lock(&priv->mcp_lock) mcp251x_hw_wake() disable_irq() <-- deadlock Use disable_irq_nosync() instead because the interrupt handler does everything while holding the mutex so it doesn't matter if it's still running. • https://git.kernel.org/stable/c/8ce8c0abcba314e1fe954a1840f6568bf5aef2ef https://git.kernel.org/stable/c/3a49b6b1caf5cefc05264d29079d52c99cb188e0 https://git.kernel.org/stable/c/513c8fc189b52f7922e36bdca58997482b198f0e https://git.kernel.org/stable/c/f7ab9e14b23a3eac6714bdc4dba244d8aa1ef646 https://git.kernel.org/stable/c/8fecde9c3f9a4b97b68bb97c9f47e5b662586ba7 https://git.kernel.org/stable/c/e554113a1cd2a9cfc6c7af7bdea2141c5757e188 https://git.kernel.org/stable/c/7dd9c26bd6cf679bcfdef01a8659791aa6487a29 •
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 •