forked from Minki/linux
82e9697250
If CONFIG_REFCOUNT_FULL=y, refcount_inc() WARN when refcount is 0. When creating a new btf, the initial btf->refcnt is 0 and triggered the following: [ 34.855452] refcount_t: increment on 0; use-after-free. [ 34.856252] WARNING: CPU: 6 PID: 1857 at lib/refcount.c:153 refcount_inc+0x26/0x30 .... [ 34.868809] Call Trace: [ 34.869168] btf_new_fd+0x1af6/0x24d0 [ 34.869645] ? btf_type_seq_show+0x200/0x200 [ 34.870212] ? lock_acquire+0x3b0/0x3b0 [ 34.870726] ? security_capable+0x54/0x90 [ 34.871247] __x64_sys_bpf+0x1b2/0x310 [ 34.871761] ? __ia32_sys_bpf+0x310/0x310 [ 34.872285] ? bad_area_access_error+0x310/0x310 [ 34.872894] do_syscall_64+0x95/0x3f0 This patch uses refcount_set() instead. Reported-by: Yonghong Song <yhs@fb.com> Tested-by: Yonghong Song <yhs@fb.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> |
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.. | ||
arraymap.c | ||
bpf_lru_list.c | ||
bpf_lru_list.h | ||
btf.c | ||
cgroup.c | ||
core.c | ||
cpumap.c | ||
devmap.c | ||
disasm.c | ||
disasm.h | ||
hashtab.c | ||
helpers.c | ||
inode.c | ||
lpm_trie.c | ||
Makefile | ||
map_in_map.c | ||
map_in_map.h | ||
offload.c | ||
percpu_freelist.c | ||
percpu_freelist.h | ||
sockmap.c | ||
stackmap.c | ||
syscall.c | ||
tnum.c | ||
verifier.c | ||
xskmap.c |