From: Tze-nan Wu Tze-nan.Wu@mediatek.com

mainline inclusion from mainline-v6.11-rc7 commit 33f339a1ba54e56bba57ee9a77c71e385ab4825c category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB2EW4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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There's a potential race when `cgroup_bpf_enabled(CGROUP_GETSOCKOPT)` is false during the execution of `BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN`, but becomes true when `BPF_CGROUP_RUN_PROG_GETSOCKOPT` is called. This inconsistency can lead to `BPF_CGROUP_RUN_PROG_GETSOCKOPT` receiving an "-EFAULT" from `__cgroup_bpf_run_filter_getsockopt(max_optlen=0)`. Scenario shown as below:

`process A` `process B` ----------- ------------ BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN enable CGROUP_GETSOCKOPT BPF_CGROUP_RUN_PROG_GETSOCKOPT (-EFAULT)

To resolve this, remove the `BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN` macro and directly uses `copy_from_sockptr` to ensure that `max_optlen` is always set before `BPF_CGROUP_RUN_PROG_GETSOCKOPT` is invoked.

Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Co-developed-by: Yanghui Li yanghui.li@mediatek.com Signed-off-by: Yanghui Li yanghui.li@mediatek.com Co-developed-by: Cheng-Jui Wang cheng-jui.wang@mediatek.com Signed-off-by: Cheng-Jui Wang cheng-jui.wang@mediatek.com Signed-off-by: Tze-nan Wu Tze-nan.Wu@mediatek.com Acked-by: Stanislav Fomichev sdf@fomichev.me Acked-by: Alexei Starovoitov ast@kernel.org Link: https://patch.msgid.link/20240830082518.23243-1-Tze-nan.Wu@mediatek.com Signed-off-by: Jakub Kicinski kuba@kernel.org Conflicts: include/linux/bpf-cgroup.h net/socket.c [The conflicts were due to not merge commit 0b05b0cd78c9] Signed-off-by: Pu Lehui pulehui@huawei.com --- include/linux/bpf-cgroup.h | 9 --------- net/socket.c | 4 ++-- 2 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index bf74485b6567..d9d5e38cfc82 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -432,14 +432,6 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, __ret; \ })

-#define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) \ -({ \ - int __ret = 0; \ - if (cgroup_bpf_enabled(CGROUP_GETSOCKOPT)) \ - get_user(__ret, optlen); \ - __ret; \ -}) - #define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, optlen, \ max_optlen, retval) \ ({ \ @@ -528,7 +520,6 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; }) #define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(atype, major, minor, access) ({ 0; }) #define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos) ({ 0; }) -#define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; }) #define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \ optlen, max_optlen, retval) ({ retval; }) #define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen, \ diff --git a/net/socket.c b/net/socket.c index 01d530af98ca..6fe73098df03 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2148,7 +2148,7 @@ int __sys_getsockopt(int fd, int level, int optname, char __user *optval, { int err, fput_needed; struct socket *sock; - int max_optlen; + int max_optlen = 0;

sock = sockfd_lookup_light(fd, &err, &fput_needed); if (!sock) @@ -2159,7 +2159,7 @@ int __sys_getsockopt(int fd, int level, int optname, char __user *optval, goto out_put;

if (!in_compat_syscall()) - max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen); + get_user(max_optlen, optlen);

if (level == SOL_SOCKET) err = sock_getsockopt(sock, level, optname, optval, optlen);