From d3f66e4116aff8dd0d5bd4067295b9ddb5e2c29c Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 24 Oct 2018 22:05:48 +0200 Subject: bpf: fix leaking uninitialized memory on pop/peek helpers Commit f1a2e44a3aec ("bpf: add queue and stack maps") added helpers with ARG_PTR_TO_UNINIT_MAP_VALUE. Meaning, the helper is supposed to fill the map value buffer with data instead of reading from it like in other helpers such as map update. However, given the buffer is allowed to be uninitialized (since we fill it in the helper anyway), it also means that the helper is obliged to wipe the memory in case of an error in order to not allow for leaking uninitialized memory. Given pop/peek is both handled inside __{stack,queue}_map_get(), lets wipe it there on error case, that is, empty stack/queue. Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Cc: Mauricio Vasquez B Acked-by: Mauricio Vasquez B Signed-off-by: Alexei Starovoitov --- kernel/bpf/queue_stack_maps.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/bpf/queue_stack_maps.c') diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c index 12a93fb37449..8bbd72d3a121 100644 --- a/kernel/bpf/queue_stack_maps.c +++ b/kernel/bpf/queue_stack_maps.c @@ -122,6 +122,7 @@ static int __queue_map_get(struct bpf_map *map, void *value, bool delete) raw_spin_lock_irqsave(&qs->lock, flags); if (queue_stack_map_is_empty(qs)) { + memset(value, 0, qs->map.value_size); err = -ENOENT; goto out; } @@ -151,6 +152,7 @@ static int __stack_map_get(struct bpf_map *map, void *value, bool delete) raw_spin_lock_irqsave(&qs->lock, flags); if (queue_stack_map_is_empty(qs)) { + memset(value, 0, qs->map.value_size); err = -ENOENT; goto out; } -- cgit v1.3-6-gb490 From 813961de3ee6474dd5703e883471fd941d6c8f69 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 22 Nov 2018 10:49:56 -0800 Subject: bpf: fix integer overflow in queue_stack_map Fix the following issues: - allow queue_stack_map for root only - fix u32 max_entries overflow - disallow value_size == 0 Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Reported-by: Wei Wu Signed-off-by: Alexei Starovoitov Cc: Mauricio Vasquez B Signed-off-by: Daniel Borkmann --- kernel/bpf/queue_stack_maps.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/bpf/queue_stack_maps.c') diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c index 8bbd72d3a121..b384ea9f3254 100644 --- a/kernel/bpf/queue_stack_maps.c +++ b/kernel/bpf/queue_stack_maps.c @@ -7,6 +7,7 @@ #include #include #include +#include #include "percpu_freelist.h" #define QUEUE_STACK_CREATE_FLAG_MASK \ @@ -45,8 +46,12 @@ static bool queue_stack_map_is_full(struct bpf_queue_stack *qs) /* Called from syscall */ static int queue_stack_map_alloc_check(union bpf_attr *attr) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 0 || + attr->value_size == 0 || attr->map_flags & ~QUEUE_STACK_CREATE_FLAG_MASK) return -EINVAL; @@ -63,15 +68,10 @@ static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr) { int ret, numa_node = bpf_map_attr_numa_node(attr); struct bpf_queue_stack *qs; - u32 size, value_size; - u64 queue_size, cost; - - size = attr->max_entries + 1; - value_size = attr->value_size; - - queue_size = sizeof(*qs) + (u64) value_size * size; + u64 size, queue_size, cost; - cost = queue_size; + size = (u64) attr->max_entries + 1; + cost = queue_size = sizeof(*qs) + size * attr->value_size; if (cost >= U32_MAX - PAGE_SIZE) return ERR_PTR(-E2BIG); -- cgit v1.3-6-gb490