ghsa-cxf4-996m-v4m3
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context
__kernel_map_pages() is a debug function which clears the valid bit in page table entry for deallocated pages to detect illegal memory accesses to freed pages.
This function set/clear the valid bit using __set_memory(). __set_memory() acquires init_mm's semaphore, and this operation may sleep. This is problematic, because __kernel_map_pages() can be called in atomic context, and thus is illegal to sleep. An example warning that this causes:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd
preempt_count: 2, expected: 0
CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[
Rewrite this function with apply_to_existing_page_range(). It is fine to not have any locking, because __kernel_map_pages() works with pages being allocated/deallocated and those pages are not changed by anyone else in the meantime.
{
"affected": [],
"aliases": [
"CVE-2024-40915"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T13:15:14Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: rewrite __kernel_map_pages() to fix sleeping in invalid context\n\n__kernel_map_pages() is a debug function which clears the valid bit in page\ntable entry for deallocated pages to detect illegal memory accesses to\nfreed pages.\n\nThis function set/clear the valid bit using __set_memory(). __set_memory()\nacquires init_mm\u0027s semaphore, and this operation may sleep. This is\nproblematic, because __kernel_map_pages() can be called in atomic context,\nand thus is illegal to sleep. An example warning that this causes:\n\nBUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578\nin_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd\npreempt_count: 2, expected: 0\nCPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37\nHardware name: riscv-virtio,qemu (DT)\nCall Trace:\n[\u003cffffffff800060dc\u003e] dump_backtrace+0x1c/0x24\n[\u003cffffffff8091ef6e\u003e] show_stack+0x2c/0x38\n[\u003cffffffff8092baf8\u003e] dump_stack_lvl+0x5a/0x72\n[\u003cffffffff8092bb24\u003e] dump_stack+0x14/0x1c\n[\u003cffffffff8003b7ac\u003e] __might_resched+0x104/0x10e\n[\u003cffffffff8003b7f4\u003e] __might_sleep+0x3e/0x62\n[\u003cffffffff8093276a\u003e] down_write+0x20/0x72\n[\u003cffffffff8000cf00\u003e] __set_memory+0x82/0x2fa\n[\u003cffffffff8000d324\u003e] __kernel_map_pages+0x5a/0xd4\n[\u003cffffffff80196cca\u003e] __alloc_pages_bulk+0x3b2/0x43a\n[\u003cffffffff8018ee82\u003e] __vmalloc_node_range+0x196/0x6ba\n[\u003cffffffff80011904\u003e] copy_process+0x72c/0x17ec\n[\u003cffffffff80012ab4\u003e] kernel_clone+0x60/0x2fe\n[\u003cffffffff80012f62\u003e] kernel_thread+0x82/0xa0\n[\u003cffffffff8003552c\u003e] kthreadd+0x14a/0x1be\n[\u003cffffffff809357de\u003e] ret_from_fork+0xe/0x1c\n\nRewrite this function with apply_to_existing_page_range(). It is fine to\nnot have any locking, because __kernel_map_pages() works with pages being\nallocated/deallocated and those pages are not changed by anyone else in the\nmeantime.",
"id": "GHSA-cxf4-996m-v4m3",
"modified": "2024-07-12T15:31:27Z",
"published": "2024-07-12T15:31:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40915"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8661a7af04991201640863ad1a0983173f84b5eb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/919f8626099d9909b9a9620b05e8c8ab06581876"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d5257ceb19d92069195254866421f425aea42915"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fb1cf0878328fe75d47f0aed0a65b30126fcefc4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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