{"id":"CVE-2022-49985","state":"PUBLISHED","title":"bpf: Don't use tnum_range on array range checking for poke descriptors","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don't use tnum_range on array range checking for poke descriptors\n\nHsin-Wei reported a KASAN splat triggered by their BPF runtime fuzzer which\nis based on a customized syzkaller:\n\n  BUG: KASAN: slab-out-of-bounds in bpf_int_jit_compile+0x1257/0x13f0\n  Read of size 8 at addr ffff888004e90b58 by task syz-executor.0/1489\n  CPU: 1 PID: 1489 Comm: syz-executor.0 Not tainted 5.19.0 #1\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS\n  1.13.0-1ubuntu1.1 04/01/2014\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x9c/0xc9\n   print_address_description.constprop.0+0x1f/0x1f0\n   ? bpf_int_jit_compile+0x1257/0x13f0\n   kasan_report.cold+0xeb/0x197\n   ? kvmalloc_node+0x170/0x200\n   ? bpf_int_jit_compile+0x1257/0x13f0\n   bpf_int_jit_compile+0x1257/0x13f0\n   ? arch_prepare_bpf_dispatcher+0xd0/0xd0\n   ? rcu_read_lock_sched_held+0x43/0x70\n   bpf_prog_select_runtime+0x3e8/0x640\n   ? bpf_obj_name_cpy+0x149/0x1b0\n   bpf_prog_load+0x102f/0x2220\n   ? __bpf_prog_put.constprop.0+0x220/0x220\n   ? find_held_lock+0x2c/0x110\n   ? __might_fault+0xd6/0x180\n   ? lock_downgrade+0x6e0/0x6e0\n   ? lock_is_held_type+0xa6/0x120\n   ? __might_fault+0x147/0x180\n   __sys_bpf+0x137b/0x6070\n   ? bpf_perf_link_attach+0x530/0x530\n   ? new_sync_read+0x600/0x600\n   ? __fget_files+0x255/0x450\n   ? lock_downgrade+0x6e0/0x6e0\n   ? fput+0x30/0x1a0\n   ? ksys_write+0x1a8/0x260\n   __x64_sys_bpf+0x7a/0xc0\n   ? syscall_enter_from_user_mode+0x21/0x70\n   do_syscall_64+0x3b/0x90\n   entry_SYSCALL_64_after_hwframe+0x63/0xcd\n  RIP: 0033:0x7f917c4e2c2d\n\nThe problem here is that a range of tnum_range(0, map->max_entries - 1) has\nlimited ability to represent the concrete tight range with the tnum as the\nset of resulting states from value + mask can result in a superset of the\nactual intended range, and as such a tnum_in(range, reg->var_off) check may\nyield true when it shouldn't, for example tnum_range(0, 2) would result in\n00XX -> v = 0000, m = 0011 such that the intended set of {0, 1, 2} is here\nrepresented by a less precise superset of {0, 1, 2, 3}. As the register is\nknown const scalar, really just use the concrete reg->var_off.value for the\nupper index check.","publishedAt":"2025-06-18T11:00:47.251Z","updatedAt":"2026-08-05T08:57:01.160Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"e8979807178434db8ceaa84dfcd44363e71e50bb","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"4f672112f8665102a5842c170be1713f8ff95919","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"a36df92c7ff7ecde2fb362241d0ab024dddd0597","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"a657182a5c5150cdfacb6640aad1d2712571a409","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.140","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.64","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.19.6","status":"unaffected","lessThanOrEqual":"5.19.*","versionType":"semver"},{"version":"6.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":["https://git.kernel.org/stable/c/e8979807178434db8ceaa84dfcd44363e71e50bb","https://git.kernel.org/stable/c/4f672112f8665102a5842c170be1713f8ff95919","https://git.kernel.org/stable/c/a36df92c7ff7ecde2fb362241d0ab024dddd0597","https://git.kernel.org/stable/c/a657182a5c5150cdfacb6640aad1d2712571a409"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49985.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49985","state":"PUBLISHED","datePublished":"2025-06-18T11:00:47.251Z","dateUpdated":"2026-08-05T08:57:01.160Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-06-18T10:57:27.386Z"},"containers":{"cna":{"title":"bpf: Don't use tnum_range on array range checking for poke descriptors","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don't use tnum_range on array range checking for poke descriptors\n\nHsin-Wei reported a KASAN splat triggered by their BPF runtime fuzzer which\nis based on a customized syzkaller:\n\n  BUG: KASAN: slab-out-of-bounds in bpf_int_jit_compile+0x1257/0x13f0\n  Read of size 8 at addr ffff888004e90b58 by task syz-executor.0/1489\n  CPU: 1 PID: 1489 Comm: syz-executor.0 Not tainted 5.19.0 #1\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS\n  1.13.0-1ubuntu1.1 04/01/2014\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x9c/0xc9\n   print_address_description.constprop.0+0x1f/0x1f0\n   ? bpf_int_jit_compile+0x1257/0x13f0\n   kasan_report.cold+0xeb/0x197\n   ? kvmalloc_node+0x170/0x200\n   ? bpf_int_jit_compile+0x1257/0x13f0\n   bpf_int_jit_compile+0x1257/0x13f0\n   ? arch_prepare_bpf_dispatcher+0xd0/0xd0\n   ? rcu_read_lock_sched_held+0x43/0x70\n   bpf_prog_select_runtime+0x3e8/0x640\n   ? bpf_obj_name_cpy+0x149/0x1b0\n   bpf_prog_load+0x102f/0x2220\n   ? __bpf_prog_put.constprop.0+0x220/0x220\n   ? find_held_lock+0x2c/0x110\n   ? __might_fault+0xd6/0x180\n   ? lock_downgrade+0x6e0/0x6e0\n   ? lock_is_held_type+0xa6/0x120\n   ? __might_fault+0x147/0x180\n   __sys_bpf+0x137b/0x6070\n   ? bpf_perf_link_attach+0x530/0x530\n   ? new_sync_read+0x600/0x600\n   ? __fget_files+0x255/0x450\n   ? lock_downgrade+0x6e0/0x6e0\n   ? fput+0x30/0x1a0\n   ? ksys_write+0x1a8/0x260\n   __x64_sys_bpf+0x7a/0xc0\n   ? syscall_enter_from_user_mode+0x21/0x70\n   do_syscall_64+0x3b/0x90\n   entry_SYSCALL_64_after_hwframe+0x63/0xcd\n  RIP: 0033:0x7f917c4e2c2d\n\nThe problem here is that a range of tnum_range(0, map->max_entries - 1) has\nlimited ability to represent the concrete tight range with the tnum as the\nset of resulting states from value + mask can result in a superset of the\nactual intended range, and as such a tnum_in(range, reg->var_off) check may\nyield true when it shouldn't, for example tnum_range(0, 2) would result in\n00XX -> v = 0000, m = 0011 such that the intended set of {0, 1, 2} is here\nrepresented by a less precise superset of {0, 1, 2, 3}. As the register is\nknown const scalar, really just use the concrete reg->var_off.value for the\nupper index check."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"e8979807178434db8ceaa84dfcd44363e71e50bb","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"4f672112f8665102a5842c170be1713f8ff95919","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"a36df92c7ff7ecde2fb362241d0ab024dddd0597","versionType":"git"},{"version":"d2e4c1e6c2947269346054ac8937ccfe9e0bcc6b","status":"affected","lessThan":"a657182a5c5150cdfacb6640aad1d2712571a409","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.140","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.64","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.19.6","status":"unaffected","lessThanOrEqual":"5.19.*","versionType":"semver"},{"version":"6.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e8979807178434db8ceaa84dfcd44363e71e50bb"},{"url":"https://git.kernel.org/stable/c/4f672112f8665102a5842c170be1713f8ff95919"},{"url":"https://git.kernel.org/stable/c/a36df92c7ff7ecde2fb362241d0ab024dddd0597"},{"url":"https://git.kernel.org/stable/c/a657182a5c5150cdfacb6640aad1d2712571a409"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is triggered by loading a crafted eBPF program via the bpf() syscall (BPF_PROG_LOAD → verifier → JIT), which is a local attack vector.\nAC:L - The attacker fully controls PROG_ARRAY max_entries and the constant tail-call index, and a public PoC reliably triggers the slab OOB during JIT with no conditions outside attacker control.\nPR:L - Exploitation requires loading BPF programs and creating a PROG_ARRAY (CAP_BPF, or unprivileged BPF where enabled); this is basic/low privilege relative to full root, consistent with other BPF verifier OOB scorings.\nUI:N - No victim action is required; the attacker triggers the bug solely by loading their own crafted BPF program.\nS:U - Impact stays within the kernel's authority (local memory corruption / potential privilege escalation); it does not cross a VM, IOMMU, or other security boundary.\nC:H - The bug is a slab out-of-bounds read of pointer-sized values from adjacent memory, and with attacker-chosen map sizes the OOB can span kilobytes, enabling high-impact disclosure primitives.\nI:H - The OOB-read pointer is passed to bpf_tail_call_direct_fixup / __bpf_arch_text_poke, which patches JIT code with a jump derived from that value, yielding a controllable integrity / control-flow corruption primitive.\nA:H - The OOB access was confirmed via KASAN as a slab-out-of-bounds read in bpf_int_jit_compile, and dereferencing a garbage target pointer can cause a kernel oops/panic."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:57:01.160Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.64"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}