linux/kernel/bpf
Yonghong Song bed2eb964c bpf: Fix a kernel verifier crash in stacksafe()
Daniel Hodges reported a kernel verifier crash when playing with sched-ext.
Further investigation shows that the crash is due to invalid memory access
in stacksafe(). More specifically, it is the following code:

    if (exact != NOT_EXACT &&
        old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
        cur->stack[spi].slot_type[i % BPF_REG_SIZE])
            return false;

The 'i' iterates old->allocated_stack.
If cur->allocated_stack < old->allocated_stack the out-of-bound
access will happen.

To fix the issue add 'i >= cur->allocated_stack' check such that if
the condition is true, stacksafe() should fail. Otherwise,
cur->stack[spi].slot_type[i % BPF_REG_SIZE] memory access is legal.

Fixes: 2793a8b015 ("bpf: exact states comparison for iterator convergence checks")
Cc: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: Daniel Hodges <hodgesd@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240812214847.213612-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-12 18:09:48 -07:00
..
preload bpf: make preloaded map iterators to display map elements count 2023-07-06 12:42:25 -07:00
arena.c bpf: Fix remap of arena. 2024-06-18 17:19:46 +02:00
arraymap.c bpf: Do not walk twice the map on free 2024-04-30 16:28:33 +02:00
bloom_filter.c bpf: Check bloom filter map value size 2024-03-27 09:56:17 -07:00
bpf_cgrp_storage.c bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case 2023-12-08 17:08:18 -08:00
bpf_inode_storage.c Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
bpf_iter.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
bpf_local_storage.c bpf: fix order of args in call to bpf_map_kvcalloc 2024-07-10 15:31:19 -07:00
bpf_lru_list.c bpf: Address KCSAN report on bpf_lru_list 2023-05-12 12:01:03 -07:00
bpf_lru_list.h bpf: lru: Remove unused declaration bpf_lru_promote() 2023-08-08 17:21:42 -07:00
bpf_lsm.c bpf: Add security_file_post_open() LSM hook to sleepable_lsm_hooks 2024-06-21 19:55:57 +02:00
bpf_struct_ops.c bpf: Use precise image size for struct_ops trampoline 2024-07-01 17:10:46 +02:00
bpf_task_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
btf.c bpf: Eliminate remaining "make W=1" warnings in kernel/bpf/btf.o 2024-07-12 17:02:26 +02:00
cgroup_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
cgroup.c bpf: Allow helper bpf_get_[ns_]current_pid_tgid() for all prog types 2024-03-19 14:24:07 -07:00
core.c bpf-next-for-netdev 2024-07-09 17:01:46 +02:00
cpumap.c net: Move flush list retrieval to where it is used. 2024-07-02 15:26:57 +02:00
cpumask.c bpf: Allow invoking kfuncs from BPF_PROG_TYPE_SYSCALL progs 2024-04-05 10:56:09 -07:00
crypto.c bpf: crypto: make state and IV dynptr nullable 2024-06-13 16:33:04 -07:00
devmap.c bpf-next-for-netdev 2024-07-09 17:01:46 +02:00
disasm.c bpf: add special internal-only MOV instruction to resolve per-CPU addrs 2024-04-03 10:29:55 -07:00
disasm.h
dispatcher.c bpf: Use arch_bpf_trampoline_size 2023-12-06 17:17:20 -08:00
hashtab.c bpf: Do not walk twice the hash map on free 2024-04-30 16:28:46 +02:00
helpers.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-11 12:58:13 -07:00
inode.c bpf: Support symbolic BPF FS delegation mount options 2024-01-24 16:21:02 -08:00
Kconfig bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of 2024-05-14 00:36:29 -07:00
link_iter.c
local_storage.c cgroup changes for v6.4-rc1 2023-04-29 10:05:22 -07:00
log.c bpf: remove redeclaration of new_n in bpf_verifier_vlog 2024-06-20 19:50:26 -07:00
lpm_trie.c bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie. 2024-03-29 11:10:41 -07:00
Makefile libbpf,bpf: Share BTF relocate-related code with kernel 2024-06-21 14:45:07 -07:00
map_in_map.c bpf: save extended inner map info for percpu array maps as well 2024-05-15 09:34:54 -07:00
map_in_map.h bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2023-12-04 17:50:26 -08:00
map_iter.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
memalloc.c mm: remove CONFIG_MEMCG_KMEM 2024-07-10 12:14:54 -07:00
mmap_unlock_work.h
mprog.c bpf: Handle bpf_mprog_query with NULL entry 2023-10-06 17:11:20 -07:00
net_namespace.c
offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-09-21 21:49:45 +02:00
percpu_freelist.c bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-11 12:05:14 -08:00
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: Avoid deadlock when using queue and stack maps from NMI 2023-09-11 19:04:49 -07:00
reuseport_array.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
ringbuf.c bpf: Fix overrunning reservations in ringbuf 2024-06-21 13:04:21 -07:00
stackmap.c bpf: Fix stackmap overflow check on 32-bit arches 2024-03-07 20:06:25 -08:00
syscall.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
sysfs_btf.c btf: Avoid weak external references 2024-04-16 16:35:13 +02:00
task_iter.c bpf: Remove unnecessary loop in task_file_seq_get_next() 2024-07-08 16:23:19 +02:00
tcx.c bpf, tcx: Get rid of tcx_link_const 2023-10-23 15:01:53 -07:00
tnum.c bpf: simplify tnum output if a fully known constant 2023-12-02 11:36:51 -08:00
token.c bpf,token: Use BIT_ULL() to convert the bit mask 2024-01-29 20:04:55 -08:00
trampoline.c Networking changes for 6.10. 2024-05-14 19:42:24 -07:00
verifier.c bpf: Fix a kernel verifier crash in stacksafe() 2024-08-12 18:09:48 -07:00