CVE-2021-47300
Linux Kernel BPF Out-of-Bounds Write
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix tail_call_reachable rejection for interpreter when jit failed During testing of f263a81451c1 ("bpf: Track subprog poke descriptors correctly and fix use-after-free") under various failure conditions, for example, when jit_subprogs() fails and tries to clean up the program to be run under the interpreter, we ran into the following freeze: [...] #127/8 tailcall_bpf2bpf_3:FAIL [...] [ 92.041251] BUG: KASAN: slab-out-of-bounds in ___bpf_prog_run+0x1b9d/0x2e20 [ 92.042408] Read of size 8 at addr ffff88800da67f68 by task test_progs/682 [ 92.043707] [ 92.044030] CPU: 1 PID: 682 Comm: test_progs Tainted: G O 5.13.0-53301-ge6c08cb33a30-dirty #87 [ 92.045542] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 92.046785] Call Trace: [ 92.047171] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.047773] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.048389] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.049019] ? ktime_get+0x117/0x130 [...] // few hundred [similar] lines more [ 92.659025] ? ktime_get+0x117/0x130 [ 92.659845] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.660738] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.661528] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.662378] ? print_usage_bug+0x50/0x50 [ 92.663221] ? print_usage_bug+0x50/0x50 [ 92.664077] ? bpf_ksym_find+0x9c/0xe0 [ 92.664887] ? ktime_get+0x117/0x130 [ 92.665624] ? kernel_text_address+0xf5/0x100 [ 92.666529] ? __kernel_text_address+0xe/0x30 [ 92.667725] ? unwind_get_return_address+0x2f/0x50 [ 92.668854] ? ___bpf_prog_run+0x15d4/0x2e20 [ 92.670185] ? ktime_get+0x117/0x130 [ 92.671130] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.672020] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.672860] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.675159] ? ktime_get+0x117/0x130 [ 92.677074] ? lock_is_held_type+0xd5/0x130 [ 92.678662] ? ___bpf_prog_run+0x15d4/0x2e20 [ 92.680046] ? ktime_get+0x117/0x130 [ 92.681285] ? __bpf_prog_run32+0x6b/0x90 [ 92.682601] ? __bpf_prog_run64+0x90/0x90 [ 92.683636] ? lock_downgrade+0x370/0x370 [ 92.684647] ? mark_held_locks+0x44/0x90 [ 92.685652] ? ktime_get+0x117/0x130 [ 92.686752] ? lockdep_hardirqs_on+0x79/0x100 [ 92.688004] ? ktime_get+0x117/0x130 [ 92.688573] ? __cant_migrate+0x2b/0x80 [ 92.689192] ? bpf_test_run+0x2f4/0x510 [ 92.689869] ? bpf_test_timer_continue+0x1c0/0x1c0 [ 92.690856] ? rcu_read_lock_bh_held+0x90/0x90 [ 92.691506] ? __kasan_slab_alloc+0x61/0x80 [ 92.692128] ? eth_type_trans+0x128/0x240 [ 92.692737] ? __build_skb+0x46/0x50 [ 92.693252] ? bpf_prog_test_run_skb+0x65e/0xc50 [ 92.693954] ? bpf_prog_test_run_raw_tp+0x2d0/0x2d0 [ 92.694639] ? __fget_light+0xa1/0x100 [ 92.695162] ? bpf_prog_inc+0x23/0x30 [ 92.695685] ? __sys_bpf+0xb40/0x2c80 [ 92.696324] ? bpf_link_get_from_fd+0x90/0x90 [ 92.697150] ? mark_held_locks+0x24/0x90 [ 92.698007] ? lockdep_hardirqs_on_prepare+0x124/0x220 [ 92.699045] ? finish_task_switch+0xe6/0x370 [ 92.700072] ? lockdep_hardirqs_on+0x79/0x100 [ 92.701233] ? finish_task_switch+0x11d/0x370 [ 92.702264] ? __switch_to+0x2c0/0x740 [ 92.703148] ? mark_held_locks+0x24/0x90 [ 92.704155] ? __x64_sys_bpf+0x45/0x50 [ 92.705146] ? do_syscall_64+0x35/0x80 [ 92.706953] ? entry_SYSCALL_64_after_hwframe+0x44/0xae [...] Turns out that the program rejection from e411901c0b77 ("bpf: allow for tailcalls in BPF subprograms for x64 JIT") is buggy since env->prog->aux->tail_call_reachable is never true. Commit ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT") added a tracker into check_max_stack_depth() which propagates the tail_call_reachable condition throughout the subprograms. This info is then assigned to the subprogram's ---truncated---
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
Dec. 26, 2024, 8:44 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47300.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47300 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47300 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Dec. 26, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST CWE-125 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.10.54 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.13.6 *cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* Changed Reference Type https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f No Types Assigned https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f Patch Changed Reference Type https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f No Types Assigned https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f Patch Changed Reference Type https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade No Types Assigned https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade Patch Changed Reference Type https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade No Types Assigned https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade Patch Changed Reference Type https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 No Types Assigned https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 Patch Changed Reference Type https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 No Types Assigned https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f Added Reference https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade Added Reference https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: bpf: Fix tail_call_reachable rejection for interpreter when jit failed During testing of f263a81451c1 ("bpf: Track subprog poke descriptors correctly and fix use-after-free") under various failure conditions, for example, when jit_subprogs() fails and tries to clean up the program to be run under the interpreter, we ran into the following freeze: [...] #127/8 tailcall_bpf2bpf_3:FAIL [...] [ 92.041251] BUG: KASAN: slab-out-of-bounds in ___bpf_prog_run+0x1b9d/0x2e20 [ 92.042408] Read of size 8 at addr ffff88800da67f68 by task test_progs/682 [ 92.043707] [ 92.044030] CPU: 1 PID: 682 Comm: test_progs Tainted: G O 5.13.0-53301-ge6c08cb33a30-dirty #87 [ 92.045542] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 92.046785] Call Trace: [ 92.047171] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.047773] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.048389] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.049019] ? ktime_get+0x117/0x130 [...] // few hundred [similar] lines more [ 92.659025] ? ktime_get+0x117/0x130 [ 92.659845] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.660738] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.661528] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.662378] ? print_usage_bug+0x50/0x50 [ 92.663221] ? print_usage_bug+0x50/0x50 [ 92.664077] ? bpf_ksym_find+0x9c/0xe0 [ 92.664887] ? ktime_get+0x117/0x130 [ 92.665624] ? kernel_text_address+0xf5/0x100 [ 92.666529] ? __kernel_text_address+0xe/0x30 [ 92.667725] ? unwind_get_return_address+0x2f/0x50 [ 92.668854] ? ___bpf_prog_run+0x15d4/0x2e20 [ 92.670185] ? ktime_get+0x117/0x130 [ 92.671130] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.672020] ? __bpf_prog_run_args32+0x8b/0xb0 [ 92.672860] ? __bpf_prog_run_args64+0xc0/0xc0 [ 92.675159] ? ktime_get+0x117/0x130 [ 92.677074] ? lock_is_held_type+0xd5/0x130 [ 92.678662] ? ___bpf_prog_run+0x15d4/0x2e20 [ 92.680046] ? ktime_get+0x117/0x130 [ 92.681285] ? __bpf_prog_run32+0x6b/0x90 [ 92.682601] ? __bpf_prog_run64+0x90/0x90 [ 92.683636] ? lock_downgrade+0x370/0x370 [ 92.684647] ? mark_held_locks+0x44/0x90 [ 92.685652] ? ktime_get+0x117/0x130 [ 92.686752] ? lockdep_hardirqs_on+0x79/0x100 [ 92.688004] ? ktime_get+0x117/0x130 [ 92.688573] ? __cant_migrate+0x2b/0x80 [ 92.689192] ? bpf_test_run+0x2f4/0x510 [ 92.689869] ? bpf_test_timer_continue+0x1c0/0x1c0 [ 92.690856] ? rcu_read_lock_bh_held+0x90/0x90 [ 92.691506] ? __kasan_slab_alloc+0x61/0x80 [ 92.692128] ? eth_type_trans+0x128/0x240 [ 92.692737] ? __build_skb+0x46/0x50 [ 92.693252] ? bpf_prog_test_run_skb+0x65e/0xc50 [ 92.693954] ? bpf_prog_test_run_raw_tp+0x2d0/0x2d0 [ 92.694639] ? __fget_light+0xa1/0x100 [ 92.695162] ? bpf_prog_inc+0x23/0x30 [ 92.695685] ? __sys_bpf+0xb40/0x2c80 [ 92.696324] ? bpf_link_get_from_fd+0x90/0x90 [ 92.697150] ? mark_held_locks+0x24/0x90 [ 92.698007] ? lockdep_hardirqs_on_prepare+0x124/0x220 [ 92.699045] ? finish_task_switch+0xe6/0x370 [ 92.700072] ? lockdep_hardirqs_on+0x79/0x100 [ 92.701233] ? finish_task_switch+0x11d/0x370 [ 92.702264] ? __switch_to+0x2c0/0x740 [ 92.703148] ? mark_held_locks+0x24/0x90 [ 92.704155] ? __x64_sys_bpf+0x45/0x50 [ 92.705146] ? do_syscall_64+0x35/0x80 [ 92.706953] ? entry_SYSCALL_64_after_hwframe+0x44/0xae [...] Turns out that the program rejection from e411901c0b77 ("bpf: allow for tailcalls in BPF subprograms for x64 JIT") is buggy since env->prog->aux->tail_call_reachable is never true. Commit ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT") added a tracker into check_max_stack_depth() which propagates the tail_call_reachable condition throughout the subprograms. This info is then assigned to the subprogram's ---truncated--- Added Reference kernel.org https://git.kernel.org/stable/c/39f1735c8107ef43a53c4daf82f330d880488d8f [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/cbb086074dab631ac43f8645cbac1d7b148e05c4 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/5dd0a6b8582ffbfa88351949d50eccd5b6694ade [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47300 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47300
weaknesses.