ghsa-737f-4c7f-cgc8
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
BPF: Fix potential bad pointer dereference in bpf_sys_bpf()
The bpf_sys_bpf() helper function allows an eBPF program to load another eBPF program from within the kernel. In this case the argument union bpf_attr pointer (as well as the insns and license pointers inside) is a kernel address instead of a userspace address (which is the case of a usual bpf() syscall). To make the memory copying process in the syscall work in both cases, bpfptr_t was introduced to wrap around the pointer and distinguish its origin. Specifically, when copying memory contents from a bpfptr_t, a copy_from_user() is performed in case of a userspace address and a memcpy() is performed for a kernel address.
This can lead to problems because the in-kernel pointer is never checked for validity. The problem happens when an eBPF syscall program tries to call bpf_sys_bpf() to load a program but provides a bad insns pointer -- say 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf() which would then call bpf_prog_load() to load the program. bpf_prog_load() is responsible for copying the eBPF instructions to the newly allocated memory for the program; it creates a kernel bpfptr_t for insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t operations are backed by the corresponding sockptr_t operations, which performs direct memcpy() on kernel pointers for copy_from/strncpy_from operations. Therefore, the code is always happy to dereference the bad pointer to trigger a un-handle-able page fault and in turn an oops. However, this is not supposed to happen because at that point the eBPF program is already verified and should not cause a memory error.
Sample KASAN trace:
[ 25.685056][ T228] ================================================================== [ 25.685680][ T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30 [ 25.686210][ T228] Read of size 80 at addr 00000000deadbeef by task poc/228 [ 25.686732][ T228] [ 25.686893][ T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7 [ 25.687375][ T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 [ 25.687991][ T228] Call Trace: [ 25.688223][ T228] [ 25.688429][ T228] dump_stack_lvl+0x73/0x9e [ 25.688747][ T228] print_report+0xea/0x200 [ 25.689061][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.689401][ T228] ? _printk+0x54/0x6e [ 25.689693][ T228] ? _raw_spin_lock_irqsave+0x70/0xd0 [ 25.690071][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.690412][ T228] kasan_report+0xb5/0xe0 [ 25.690716][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691059][ T228] kasan_check_range+0x2bd/0x2e0 [ 25.691405][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691734][ T228] memcpy+0x25/0x60 [ 25.692000][ T228] copy_from_bpfptr+0x21/0x30 [ 25.692328][ T228] bpf_prog_load+0x604/0x9e0 [ 25.692653][ T228] ? cap_capable+0xb4/0xe0 [ 25.692956][ T228] ? security_capable+0x4f/0x70 [ 25.693324][ T228] __sys_bpf+0x3af/0x580 [ 25.693635][ T228] bpf_sys_bpf+0x45/0x240 [ 25.693937][ T228] bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd [ 25.694394][ T228] bpf_prog_run_pin_on_cpu+0x2f/0xb0 [ 25.694756][ T228] bpf_prog_test_run_syscall+0x146/0x1c0 [ 25.695144][ T228] bpf_prog_test_run+0x172/0x190 [ 25.695487][ T228] __sys_bpf+0x2c5/0x580 [ 25.695776][ T228] __x64_sys_bpf+0x3a/0x50 [ 25.696084][ T228] do_syscall_64+0x60/0x90 [ 25.696393][ T228] ? fpregs_assert_state_consistent+0x50/0x60 [ 25.696815][ T228] ? exit_to_user_mode_prepare+0x36/0xa0 [ 25.697202][ T228] ? syscall_exit_to_user_mode+0x20/0x40 [ 25.697586][ T228] ? do_syscall_64+0x6e/0x90 [ 25.697899][ T228] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 25.698312][ T228] RIP: 0033:0x7f6d543fb759 [ 25.698624][ T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d ---truncated---
{
"affected": [],
"aliases": [
"CVE-2022-50069"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-18T11:15:35Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBPF: Fix potential bad pointer dereference in bpf_sys_bpf()\n\nThe bpf_sys_bpf() helper function allows an eBPF program to load another\neBPF program from within the kernel. In this case the argument union\nbpf_attr pointer (as well as the insns and license pointers inside) is a\nkernel address instead of a userspace address (which is the case of a\nusual bpf() syscall). To make the memory copying process in the syscall\nwork in both cases, bpfptr_t was introduced to wrap around the pointer\nand distinguish its origin. Specifically, when copying memory contents\nfrom a bpfptr_t, a copy_from_user() is performed in case of a userspace\naddress and a memcpy() is performed for a kernel address.\n\nThis can lead to problems because the in-kernel pointer is never checked\nfor validity. The problem happens when an eBPF syscall program tries to\ncall bpf_sys_bpf() to load a program but provides a bad insns pointer --\nsay 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf()\nwhich would then call bpf_prog_load() to load the program.\nbpf_prog_load() is responsible for copying the eBPF instructions to the\nnewly allocated memory for the program; it creates a kernel bpfptr_t for\ninsns and invokes copy_from_bpfptr(). Internally, all bpfptr_t\noperations are backed by the corresponding sockptr_t operations, which\nperforms direct memcpy() on kernel pointers for copy_from/strncpy_from\noperations. Therefore, the code is always happy to dereference the bad\npointer to trigger a un-handle-able page fault and in turn an oops.\nHowever, this is not supposed to happen because at that point the eBPF\nprogram is already verified and should not cause a memory error.\n\nSample KASAN trace:\n\n[ 25.685056][ T228] ==================================================================\n[ 25.685680][ T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30\n[ 25.686210][ T228] Read of size 80 at addr 00000000deadbeef by task poc/228\n[ 25.686732][ T228]\n[ 25.686893][ T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7\n[ 25.687375][ T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014\n[ 25.687991][ T228] Call Trace:\n[ 25.688223][ T228] \u003cTASK\u003e\n[ 25.688429][ T228] dump_stack_lvl+0x73/0x9e\n[ 25.688747][ T228] print_report+0xea/0x200\n[ 25.689061][ T228] ? copy_from_bpfptr+0x21/0x30\n[ 25.689401][ T228] ? _printk+0x54/0x6e\n[ 25.689693][ T228] ? _raw_spin_lock_irqsave+0x70/0xd0\n[ 25.690071][ T228] ? copy_from_bpfptr+0x21/0x30\n[ 25.690412][ T228] kasan_report+0xb5/0xe0\n[ 25.690716][ T228] ? copy_from_bpfptr+0x21/0x30\n[ 25.691059][ T228] kasan_check_range+0x2bd/0x2e0\n[ 25.691405][ T228] ? copy_from_bpfptr+0x21/0x30\n[ 25.691734][ T228] memcpy+0x25/0x60\n[ 25.692000][ T228] copy_from_bpfptr+0x21/0x30\n[ 25.692328][ T228] bpf_prog_load+0x604/0x9e0\n[ 25.692653][ T228] ? cap_capable+0xb4/0xe0\n[ 25.692956][ T228] ? security_capable+0x4f/0x70\n[ 25.693324][ T228] __sys_bpf+0x3af/0x580\n[ 25.693635][ T228] bpf_sys_bpf+0x45/0x240\n[ 25.693937][ T228] bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd\n[ 25.694394][ T228] bpf_prog_run_pin_on_cpu+0x2f/0xb0\n[ 25.694756][ T228] bpf_prog_test_run_syscall+0x146/0x1c0\n[ 25.695144][ T228] bpf_prog_test_run+0x172/0x190\n[ 25.695487][ T228] __sys_bpf+0x2c5/0x580\n[ 25.695776][ T228] __x64_sys_bpf+0x3a/0x50\n[ 25.696084][ T228] do_syscall_64+0x60/0x90\n[ 25.696393][ T228] ? fpregs_assert_state_consistent+0x50/0x60\n[ 25.696815][ T228] ? exit_to_user_mode_prepare+0x36/0xa0\n[ 25.697202][ T228] ? syscall_exit_to_user_mode+0x20/0x40\n[ 25.697586][ T228] ? do_syscall_64+0x6e/0x90\n[ 25.697899][ T228] entry_SYSCALL_64_after_hwframe+0x63/0xcd\n[ 25.698312][ T228] RIP: 0033:0x7f6d543fb759\n[ 25.698624][ T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d \n---truncated---",
"id": "GHSA-737f-4c7f-cgc8",
"modified": "2025-06-18T12:30:46Z",
"published": "2025-06-18T12:30:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50069"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1f6db7148ed7382b336c5827af33b5d9e992630e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/41fd6cc88aaf7058b9dfc9c7a09cc80f99c8c830"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e2dcac2f58f5a95ab092d1da237ffdc0da1832cf"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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