diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2025-07-31 01:47:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 16:39:14 +0200 |
| commit | e5f141ed16f7818fc63c8275176bf86494a1d38a (patch) | |
| tree | 9eb5ed8e24f68779c509397272a2258648af7515 | |
| parent | 8775ab4d39ff509d526de72ec298cfa54599eaab (diff) | |
bpf: Add cookie object to bpf maps
[ Upstream commit 12df58ad294253ac1d8df0c9bb9cf726397a671d ]
Add a cookie to BPF maps to uniquely identify BPF maps for the timespan
when the node is up. This is different to comparing a pointer or BPF map
id which could get rolled over and reused.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: abad3d0bad72 ("bpf: Fix oob access in cgroup local storage")
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5b25d278409b..f9900a23ca16 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -310,6 +310,7 @@ struct bpf_map { bool free_after_rcu_gp; atomic64_t sleepable_refcnt; s64 __percpu *elem_count; + u64 cookie; /* write-once */ }; static inline const char *btf_field_type_name(enum btf_field_type type) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index dd5304c6ac3c..82ae4fadecf0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -37,6 +37,7 @@ #include <linux/trace_events.h> #include <linux/tracepoint.h> #include <linux/overflow.h> +#include <linux/cookie.h> #include <net/netfilter/nf_bpf_link.h> #include <net/netkit.h> @@ -53,6 +54,7 @@ #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) DEFINE_PER_CPU(int, bpf_prog_active); +DEFINE_COOKIE(bpf_map_cookie); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); static DEFINE_IDR(map_idr); @@ -1487,6 +1489,10 @@ static int map_create(union bpf_attr *attr, bool kernel) if (err < 0) goto free_map; + preempt_disable(); + map->cookie = gen_cookie_next(&bpf_map_cookie); + preempt_enable(); + atomic64_set(&map->refcnt, 1); atomic64_set(&map->usercnt, 1); mutex_init(&map->freeze_mutex); |