CVE-2022-49985

In the Linux kernel, the following vulnerability has been resolved: bpf: Don't use tnum_range on array range checking for poke descriptors Hsin-Wei reported a KASAN splat triggered by their BPF runtime fuzzer which is based on a customized syzkaller: BUG: KASAN: slab-out-of-bounds in bpf_int_jit_compile+0x1257/0x13f0 Read of size 8 at addr ffff888004e90b58 by task syz-executor.0/1489 CPU: 1 PID: 1489 Comm: syz-executor.0 Not tainted 5.19.0 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x9c/0xc9 print_address_description.constprop.0+0x1f/0x1f0 ? bpf_int_jit_compile+0x1257/0x13f0 kasan_report.cold+0xeb/0x197 ? kvmalloc_node+0x170/0x200 ? bpf_int_jit_compile+0x1257/0x13f0 bpf_int_jit_compile+0x1257/0x13f0 ? arch_prepare_bpf_dispatcher+0xd0/0xd0 ? rcu_read_lock_sched_held+0x43/0x70 bpf_prog_select_runtime+0x3e8/0x640 ? bpf_obj_name_cpy+0x149/0x1b0 bpf_prog_load+0x102f/0x2220 ? __bpf_prog_put.constprop.0+0x220/0x220 ? find_held_lock+0x2c/0x110 ? __might_fault+0xd6/0x180 ? lock_downgrade+0x6e0/0x6e0 ? lock_is_held_type+0xa6/0x120 ? __might_fault+0x147/0x180 __sys_bpf+0x137b/0x6070 ? bpf_perf_link_attach+0x530/0x530 ? new_sync_read+0x600/0x600 ? __fget_files+0x255/0x450 ? lock_downgrade+0x6e0/0x6e0 ? fput+0x30/0x1a0 ? ksys_write+0x1a8/0x260 __x64_sys_bpf+0x7a/0xc0 ? syscall_enter_from_user_mode+0x21/0x70 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f917c4e2c2d The problem here is that a range of tnum_range(0, map->max_entries - 1) has limited ability to represent the concrete tight range with the tnum as the set of resulting states from value + mask can result in a superset of the actual intended range, and as such a tnum_in(range, reg->var_off) check may yield true when it shouldn't, for example tnum_range(0, 2) would result in 00XX -> v = 0000, m = 0011 such that the intended set of {0, 1, 2} is here represented by a less precise superset of {0, 1, 2, 3}. As the register is known const scalar, really just use the concrete reg->var_off.value for the upper index check.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:*

History

14 Nov 2025, 18:14

Type Values Removed Values Added
First Time Linux
Linux linux Kernel
CPE cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.1
CWE CWE-125
References () https://git.kernel.org/stable/c/4f672112f8665102a5842c170be1713f8ff95919 - () https://git.kernel.org/stable/c/4f672112f8665102a5842c170be1713f8ff95919 - Patch
References () https://git.kernel.org/stable/c/a36df92c7ff7ecde2fb362241d0ab024dddd0597 - () https://git.kernel.org/stable/c/a36df92c7ff7ecde2fb362241d0ab024dddd0597 - Patch
References () https://git.kernel.org/stable/c/a657182a5c5150cdfacb6640aad1d2712571a409 - () https://git.kernel.org/stable/c/a657182a5c5150cdfacb6640aad1d2712571a409 - Patch
References () https://git.kernel.org/stable/c/e8979807178434db8ceaa84dfcd44363e71e50bb - () https://git.kernel.org/stable/c/e8979807178434db8ceaa84dfcd44363e71e50bb - Patch
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf: No use tnum_range en la comprobación del rango de matriz para los descriptores de poke Hsin-Wei informó un splat de KASAN activado por su fuzzer de tiempo de ejecución BPF que se basa en un syzkaller personalizado: ERROR: KASAN: slab-out-of-bounds en bpf_int_jit_compile+0x1257/0x13f0 Lectura de tamaño 8 en la dirección ffff888004e90b58 por la tarea syz-executor.0/1489 CPU: 1 PID: 1489 Comm: syz-executor.0 No contaminado 5.19.0 #1 Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 01/04/2014 Rastreo de llamadas: dump_stack_lvl+0x9c/0xc9 print_address_description.constprop.0+0x1f/0x1f0 ? bpf_int_jit_compile+0x1257/0x13f0 kasan_report.cold+0xeb/0x197 ? kvmalloc_node+0x170/0x200 ? bpf_int_jit_compile+0x1257/0x13f0 bpf_int_jit_compile+0x1257/0x13f0 ? arch_prepare_bpf_dispatcher+0xd0/0xd0 ? rcu_read_lock_sched_held+0x43/0x70 bpf_prog_select_runtime+0x3e8/0x640 ? bpf_obj_name_cpy+0x149/0x1b0 bpf_prog_load+0x102f/0x2220 ? __bpf_prog_put.constprop.0+0x220/0x220 ? find_held_lock+0x2c/0x110 ? __might_fault+0xd6/0x180 ? lock_downgrade+0x6e0/0x6e0 ? lock_is_held_type+0xa6/0x120 ? __might_fault+0x147/0x180 __sys_bpf+0x137b/0x6070 ? bpf_perf_link_attach+0x530/0x530 ? new_sync_read+0x600/0x600 ? __fget_files+0x255/0x450 ? lock_downgrade+0x6e0/0x6e0 ? fput+0x30/0x1a0 ? ksys_write+0x1a8/0x260 __x64_sys_bpf+0x7a/0xc0 ? syscall_enter_from_user_mode+0x21/0x70 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f917c4e2c2d El problema aquí es que un rango de tnum_range(0, map-&gt;max_entries - 1) tiene una capacidad limitada para representar el rango estrecho concreto con el tnum como el conjunto de estados resultantes de value + mask puede resultar en un superconjunto del rango real deseado, y como tal una comprobación tnum_in(range, reg-&gt;var_off) puede dar como resultado verdadero cuando no debería, por ejemplo tnum_range(0, 2) daría como resultado 00XX -&gt; v = 0000, m = 0011 de modo que el conjunto deseado de {0, 1, 2} está representado aquí por un superconjunto menos preciso de {0, 1, 2, 3}. Como el registro es un escalar constante, simplemente use el valor concreto reg-&gt;var_off.value para la verificación del índice superior.

18 Jun 2025, 11:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-06-18 11:15

Updated : 2025-11-14 18:14


NVD link : CVE-2022-49985

Mitre link : CVE-2022-49985

CVE.ORG link : CVE-2022-49985


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-125

Out-of-bounds Read