From: Daniel Borkmann <daniel@iogearbox.net> mainline inclusion from mainline-v6.17-rc1 commit 12df58ad294253ac1d8df0c9bb9cf726397a671d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICTB0G CVE: CVE-2025-38502 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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> Conflicts: include/linux/bpf.h kernel/bpf/syscall.c [The conflicts were due to some minor issue.] Signed-off-by: Xiaomeng Zhang <zhangxiaomeng13@huawei.com> --- include/linux/bpf.h | 1 + kernel/bpf/syscall.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5d3f5fb86d02..0cd222746784 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -304,6 +304,7 @@ struct bpf_map { bool free_after_mult_rcu_gp; KABI_FILL_HOLE(bool free_after_rcu_gp) s64 __percpu *elem_count; + u64 cookie; /* write-once */ KABI_USE(1, atomic64_t sleepable_refcnt) KABI_USE(2, const struct btf_type *attach_func_proto) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7131d7bf92d7..150f524198be 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -35,6 +35,7 @@ #include <linux/rcupdate_trace.h> #include <linux/memcontrol.h> #include <linux/trace_events.h> +#include <linux/cookie.h> #include <net/netfilter/nf_bpf_link.h> #include <linux/bpf_sched.h> @@ -51,6 +52,7 @@ #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); @@ -1254,6 +1256,10 @@ static int map_create(union bpf_attr *attr) 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); -- 2.34.1