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Filename Latest commit message Latest commit date
Eric Dumazet e412b3d178 bpf, arm64: Clear prog->jited_len along prog->jited
[ Upstream commit 10f3b29c65bb2fe0d47c2945cd0b4087be1c5218 ]

syzbot reported an illegal copy_to_user() attempt
from bpf_prog_get_info_by_fd() [1]

There was no repro yet on this bug, but I think
that commit 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns")
is exposing a prior bug in bpf arm64.

bpf_prog_get_info_by_fd() looks at prog->jited_len
to determine if the JIT image can be copied out to user space.

My theory is that syzbot managed to get a prog where prog->jited_len
has been set to 43, while prog->bpf_func has ben cleared.

It is not clear why copy_to_user(uinsns, NULL, ulen) is triggering
this particular warning.

I thought find_vma_area(NULL) would not find a vm_struct.
As we do not hold vmap_area_lock spinlock, it might be possible
that the found vm_struct was garbage.

[1]
usercopy: Kernel memory exposure attempt detected from vmalloc (offset 792633534417210172, size 43)!
kernel BUG at mm/usercopy.c:101!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 25002 Comm: syz-executor.1 Not tainted 5.18.0-syzkaller-10139-g8291eaafed36 #0
Hardware name: linux,dummy-virt (DT)
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : usercopy_abort+0x90/0x94 mm/usercopy.c:101
lr : usercopy_abort+0x90/0x94 mm/usercopy.c:89
sp : ffff80000b773a20
x29: ffff80000b773a30 x28: faff80000b745000 x27: ffff80000b773b48
x26: 0000000000000000 x25: 000000000000002b x24: 0000000000000000
x23: 00000000000000e0 x22: ffff80000b75db67 x21: 0000000000000001
x20: 000000000000002b x19: ffff80000b75db3c x18: 00000000fffffffd
x17: 2820636f6c6c616d x16: 76206d6f72662064 x15: 6574636574656420
x14: 74706d6574746120 x13: 2129333420657a69 x12: 73202c3237313031
x11: 3237313434333533 x10: 3336323937207465 x9 : 657275736f707865
x8 : ffff80000a30c550 x7 : ffff80000b773830 x6 : ffff80000b773830
x5 : 0000000000000000 x4 : ffff00007fbbaa10 x3 : 0000000000000000
x2 : 0000000000000000 x1 : f7ff000028fc0000 x0 : 0000000000000064
Call trace:
 usercopy_abort+0x90/0x94 mm/usercopy.c:89
 check_heap_object mm/usercopy.c:186 [inline]
 __check_object_size mm/usercopy.c:252 [inline]
 __check_object_size+0x198/0x36c mm/usercopy.c:214
 check_object_size include/linux/thread_info.h:199 [inline]
 check_copy_size include/linux/thread_info.h:235 [inline]
 copy_to_user include/linux/uaccess.h:159 [inline]
 bpf_prog_get_info_by_fd.isra.0+0xf14/0xfdc kernel/bpf/syscall.c:3993
 bpf_obj_get_info_by_fd+0x12c/0x510 kernel/bpf/syscall.c:4253
 __sys_bpf+0x900/0x2150 kernel/bpf/syscall.c:4956
 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5019 [inline]
 __arm64_sys_bpf+0x28/0x40 kernel/bpf/syscall.c:5019
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52
 el0_svc_common.constprop.0+0x44/0xec arch/arm64/kernel/syscall.c:142
 do_el0_svc+0xa0/0xc0 arch/arm64/kernel/syscall.c:206
 el0_svc+0x44/0xb0 arch/arm64/kernel/entry-common.c:624
 el0t_64_sync_handler+0x1ac/0x1b0 arch/arm64/kernel/entry-common.c:642
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:581
Code: aa0003e3 d00038c0 91248000 97fff65f (d4210000)

Fixes: db496944fd ("bpf: arm64: add JIT support for multi-function programs")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220531215113.1100754-1-eric.dumazet@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:57 +02:00
arch bpf, arm64: Clear prog->jited_len along prog->jited 2022-06-14 18:11:57 +02:00
block block: fix bio_clone_blkg_association() to associate with proper blkcg_gq 2022-06-14 18:11:50 +02:00
certs
crypto crypto: cryptd - Protect per-CPU resource by disabling BH. 2022-06-14 18:11:41 +02:00
Documentation dt-bindings: gpio: altera: correct interrupt-cells 2022-06-14 18:11:49 +02:00
drivers xen: unexport __init-annotated xen_xlate_map_ballooned_pages() 2022-06-14 18:11:57 +02:00
fs NFSv4: Don't hold the layoutget locks across multiple RPC calls 2022-06-14 18:11:57 +02:00
include net: sched: add barrier to fix packet stuck problem for lockless qdisc 2022-06-14 18:11:55 +02:00
init Kconfig: add config option for asm goto w/ outputs 2022-06-14 18:11:50 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-14 18:11:41 +02:00
kernel tracing: Avoid adding tracer option before update_tracer_options 2022-06-14 18:11:56 +02:00
lib assoc_array: Fix BUG_ON during garbage collect 2022-06-06 08:33:50 +02:00
LICENSES
mm hugetlb: fix huge_pmd_unshare address update 2022-06-14 18:11:48 +02:00
net af_unix: Fix a data-race in unix_dgram_peer_wake_me(). 2022-06-14 18:11:57 +02:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts modpost: fix removing numeric suffixes 2022-06-14 18:11:55 +02:00
security efi: Do not import certificates from UEFI Secure Boot for T2 Macs 2022-06-14 18:11:44 +02:00
sound ASoC: fsl_sai: Fix FSL_SAI_xDR/xFR definition 2022-06-14 18:11:54 +02:00
tools netfilter: nat: really support inet nat without l3 address 2022-06-14 18:11:57 +02:00
usr
virt KVM: Prevent module exit until all VMs are freed 2022-04-15 14:18:27 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
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.gitignore
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COPYING
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MAINTAINERS
Makefile Linux 5.4.197 2022-06-06 08:33:51 +02:00
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