ghsa-w983-x7cf-qq48
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix use-after-free for dynamic ftrace_ops
KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred.
In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization.
However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem.
[1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468
CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...]
Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...]
Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...]
{
"affected": [],
"aliases": [
"CVE-2022-49892"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T15:16:14Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Fix use-after-free for dynamic ftrace_ops\n\nKASAN reported a use-after-free with ftrace ops [1]. It was found from\nvmcore that perf had registered two ops with the same content\nsuccessively, both dynamic. After unregistering the second ops, a\nuse-after-free occurred.\n\nIn ftrace_shutdown(), when the second ops is unregistered, the\nFTRACE_UPDATE_CALLS command is not set because there is another enabled\nops with the same content. Also, both ops are dynamic and the ftrace\ncallback function is ftrace_ops_list_func, so the\nFTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value\nof \u0027command\u0027 will be 0 and ftrace_shutdown() will skip the rcu\nsynchronization.\n\nHowever, ftrace may be activated. When the ops is released, another CPU\nmay be accessing the ops. Add the missing synchronization to fix this\nproblem.\n\n[1]\nBUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]\nBUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049\nRead of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468\n\nCPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7\nHardware name: linux,dummy-virt (DT)\nCall trace:\n dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132\n show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196\n __dump_stack lib/dump_stack.c:77 [inline]\n dump_stack+0x1b4/0x248 lib/dump_stack.c:118\n print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387\n __kasan_report mm/kasan/report.c:547 [inline]\n kasan_report+0x118/0x210 mm/kasan/report.c:564\n check_memory_region_inline mm/kasan/generic.c:187 [inline]\n __asan_load8+0x98/0xc0 mm/kasan/generic.c:253\n __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]\n ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049\n ftrace_graph_call+0x0/0x4\n __might_sleep+0x8/0x100 include/linux/perf_event.h:1170\n __might_fault mm/memory.c:5183 [inline]\n __might_fault+0x58/0x70 mm/memory.c:5171\n do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]\n strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139\n getname_flags+0xb0/0x31c fs/namei.c:149\n getname+0x2c/0x40 fs/namei.c:209\n [...]\n\nAllocated by task 14445:\n kasan_save_stack+0x24/0x50 mm/kasan/common.c:48\n kasan_set_track mm/kasan/common.c:56 [inline]\n __kasan_kmalloc mm/kasan/common.c:479 [inline]\n __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449\n kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493\n kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950\n kmalloc include/linux/slab.h:563 [inline]\n kzalloc include/linux/slab.h:675 [inline]\n perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230\n perf_event_alloc kernel/events/core.c:11733 [inline]\n __do_sys_perf_event_open kernel/events/core.c:11831 [inline]\n __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723\n __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723\n [...]\n\nFreed by task 14445:\n kasan_save_stack+0x24/0x50 mm/kasan/common.c:48\n kasan_set_track+0x24/0x34 mm/kasan/common.c:56\n kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358\n __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437\n __kasan_slab_free mm/kasan/common.c:445 [inline]\n kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446\n slab_free_hook mm/slub.c:1569 [inline]\n slab_free_freelist_hook mm/slub.c:1608 [inline]\n slab_free mm/slub.c:3179 [inline]\n kfree+0x12c/0xc10 mm/slub.c:4176\n perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434\n perf_event_alloc kernel/events/core.c:11733 [inline]\n __do_sys_perf_event_open kernel/events/core.c:11831 [inline]\n __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723\n [...]",
"id": "GHSA-w983-x7cf-qq48",
"modified": "2025-05-01T15:31:52Z",
"published": "2025-05-01T15:31:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49892"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0e792b89e6800cd9cb4757a76a96f7ef3e8b6294"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/88561a66777e7a2fe06638c6dcb22a9fae0b6733"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cc1b9961a0ceb70f6ca4e2f4b8bb71c87c7a495c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ea5f2fd4640ecbb9df969bf8bb27733ae2183169"
}
],
"schema_version": "1.4.0",
"severity": []
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.