linux/kernel/bpf
Alexei Starovoitov 18644cec71 bpf: Fix use-after-free in fmod_ret check
Fix the following issue:
[  436.749342] BUG: KASAN: use-after-free in bpf_trampoline_put+0x39/0x2a0
[  436.749995] Write of size 4 at addr ffff8881ef38b8a0 by task kworker/3:5/2243
[  436.750712]
[  436.752677] Workqueue: events bpf_prog_free_deferred
[  436.753183] Call Trace:
[  436.756483]  bpf_trampoline_put+0x39/0x2a0
[  436.756904]  bpf_prog_free_deferred+0x16d/0x3d0
[  436.757377]  process_one_work+0x94a/0x15b0
[  436.761969]
[  436.762130] Allocated by task 2529:
[  436.763323]  bpf_trampoline_lookup+0x136/0x540
[  436.763776]  bpf_check+0x2872/0xa0a8
[  436.764144]  bpf_prog_load+0xb6f/0x1350
[  436.764539]  __do_sys_bpf+0x16d7/0x3720
[  436.765825]
[  436.765988] Freed by task 2529:
[  436.767084]  kfree+0xc6/0x280
[  436.767397]  bpf_trampoline_put+0x1fd/0x2a0
[  436.767826]  bpf_check+0x6832/0xa0a8
[  436.768197]  bpf_prog_load+0xb6f/0x1350
[  436.768594]  __do_sys_bpf+0x16d7/0x3720

prog->aux->trampoline = tr should be set only when prog is valid.
Otherwise prog freeing will try to put trampoline via prog->aux->trampoline,
but it may not point to a valid trampoline.

Fixes: 6ba43b761c ("bpf: Attachment verification for BPF_MODIFY_RETURN")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200529043839.15824-2-alexei.starovoitov@gmail.com
2020-05-29 22:25:58 +02:00
..
arraymap.c bpf: Fix bug in mmap() implementation for BPF array map 2020-05-14 12:40:04 -07:00
bpf_lru_list.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
bpf_lru_list.h bpf: Fix a typo "inacitve" -> "inactive" 2020-04-06 21:54:10 +02:00
bpf_lsm.c bpf: lsm: Implement attach, detach and execution 2020-03-30 01:34:00 +02:00
bpf_struct_ops_types.h bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
bpf_struct_ops.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
btf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-03-30 19:52:37 -07:00
cgroup.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-03-30 19:52:37 -07:00
core.c bpf: Enable bpf cgroup hooks to retrieve cgroup v2 and ancestor id 2020-03-27 19:40:39 -07:00
cpumap.c cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabled 2020-04-20 18:38:04 -07:00
devmap.c bpf, xdp: Remove no longer required rcu_read_{un}lock() 2020-01-27 11:16:25 +01:00
disasm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
disasm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
dispatcher.c bpf: Remove bpf_image tree 2020-03-13 12:49:52 -07:00
hashtab.c bpf: Replace zero-length array with flexible-array member 2020-02-28 01:21:02 +01:00
helpers.c bpf: Enable bpf cgroup hooks to retrieve cgroup v2 and ancestor id 2020-03-27 19:40:39 -07:00
inode.c bpf: Introduce pinnable bpf_link abstraction 2020-03-02 22:06:27 -08:00
local_storage.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
lpm_trie.c bpf: Replace zero-length array with flexible-array member 2020-02-28 01:21:02 +01:00
Makefile bpf: Introduce BPF_PROG_TYPE_LSM 2020-03-30 01:34:00 +02:00
map_in_map.c bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS 2020-01-09 08:46:18 -08:00
map_in_map.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
offload.c bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill 2020-02-17 16:53:49 +01:00
percpu_freelist.c bpf: Dont iterate over possible CPUs with interrupts disabled 2020-02-24 16:18:20 -08:00
percpu_freelist.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
queue_stack_maps.c bpf: move memory size checks to bpf_map_charge_init() 2019-05-31 16:52:56 -07:00
reuseport_array.c net: Generate reuseport group ID on group creation 2020-02-21 22:29:45 +01:00
stackmap.c bpf/stackmap: Dont trylock mmap_sem with PREEMPT_RT and interrupts disabled 2020-02-24 16:20:10 -08:00
syscall.c bpf: Prevent mmap()'ing read-only maps as writable 2020-05-20 20:21:53 -07:00
sysfs_btf.c bpf: Support llvm-objcopy for vmlinux BTF 2020-03-19 12:32:38 +01:00
tnum.c bpf: Verifier, do explicit ALU32 bounds tracking 2020-03-30 14:59:53 -07:00
trampoline.c bpf: lsm: Implement attach, detach and execution 2020-03-30 01:34:00 +02:00
verifier.c bpf: Fix use-after-free in fmod_ret check 2020-05-29 22:25:58 +02:00
xskmap.c xsk: Make xskmap flush_list common for all map instances 2019-12-19 21:09:43 -08:00