mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command 

Seems like that extra bpf_capable() check in BPF_MAP_FREEZE handler was
unintentionally left when we switched to a model that all BPF map
operations should be allowed regardless of CAP_BPF (or any other
capabilities), as long as process got BPF map FD somehow.

This patch replaces bpf_capable() check in BPF_MAP_FREEZE handler with
writeable access check, given conceptually freezing the map is modifying
it: map becomes unmodifiable for subsequent updates.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230524225421.1587859-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2023-05-24 15:54:19 -07:00 committed by Alexei Starovoitov
parent fcf1fa29c8
commit c4c84f6fb2
1 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
kernel/bpf/syscall.c
View File

@ -1931,6 +1931,11 @@ static int map_freeze(const union bpf_attr *attr)
return -ENOTSUPP;
}
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
mutex_lock(&map->freeze_mutex);
if (bpf_map_write_active(map)) {
err = -EBUSY;
@ -1940,10 +1945,6 @@ static int map_freeze(const union bpf_attr *attr)
err = -EBUSY;
goto err_put;
}
if (!bpf_capable()) {
err = -EPERM;
goto err_put;
}
WRITE_ONCE(map->frozen, true);
err_put: