From 301a33d51880619d0c5a581b5a48d3a5248fa84b Mon Sep 17 00:00:00 2001 From: Mircea Cirjaliu Date: Tue, 19 Jan 2021 21:53:18 +0100 Subject: [PATCH 1/3] bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback I assume this was obtained by copy/paste. Point it to bpf_map_peek_elem() instead of bpf_map_pop_elem(). In practice it may have been less likely hit when under JIT given shielded via 84430d4232c3 ("bpf, verifier: avoid retpoline for map push/pop/peek operation"). Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Signed-off-by: Mircea Cirjaliu Signed-off-by: Daniel Borkmann Cc: Mauricio Vasquez Link: https://lore.kernel.org/bpf/AM7PR02MB6082663DFDCCE8DA7A6DD6B1BBA30@AM7PR02MB6082.eurprd02.prod.outlook.com --- kernel/bpf/helpers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index bd8a3183d030..41ca280b1dc1 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -108,7 +108,7 @@ BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value) } const struct bpf_func_proto bpf_map_peek_elem_proto = { - .func = bpf_map_pop_elem, + .func = bpf_map_peek_elem, .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_CONST_MAP_PTR, From b425e24a934e21a502d25089c6c7443d799c5594 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Mon, 18 Jan 2021 18:03:33 +0200 Subject: [PATCH 2/3] xsk: Clear pool even for inactive queues MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The number of queues can change by other means, rather than ethtool. For example, attaching an mqprio qdisc with num_tc > 1 leads to creating multiple sets of TX queues, which may be then destroyed when mqprio is deleted. If an AF_XDP socket is created while mqprio is active, dev->_tx[queue_id].pool will be filled, but then real_num_tx_queues may decrease with deletion of mqprio, which will mean that the pool won't be NULLed, and a further increase of the number of TX queues may expose a dangling pointer. To avoid any potential misbehavior, this commit clears pool for RX and TX queues, regardless of real_num_*_queues, still taking into consideration num_*_queues to avoid overflows. Fixes: 1c1efc2af158 ("xsk: Create and free buffer pool independently from umem") Fixes: a41b4f3c58dd ("xsk: simplify xdp_clear_umem_at_qid implementation") Signed-off-by: Maxim Mikityanskiy Signed-off-by: Daniel Borkmann Acked-by: Björn Töpel Link: https://lore.kernel.org/bpf/20210118160333.333439-1-maximmi@mellanox.com --- net/xdp/xsk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 8037b04a9edd..4a83117507f5 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -108,9 +108,9 @@ EXPORT_SYMBOL(xsk_get_pool_from_qid); void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id) { - if (queue_id < dev->real_num_rx_queues) + if (queue_id < dev->num_rx_queues) dev->_rx[queue_id].pool = NULL; - if (queue_id < dev->real_num_tx_queues) + if (queue_id < dev->num_tx_queues) dev->_tx[queue_id].pool = NULL; } From bc895e8b2a64e502fbba72748d59618272052a8b Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 20 Jan 2021 00:24:24 +0100 Subject: [PATCH 3/3] bpf: Fix signed_{sub,add32}_overflows type handling Fix incorrect signed_{sub,add32}_overflows() input types (and a related buggy comment). It looks like this might have slipped in via copy/paste issue, also given prior to 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") the signature of signed_sub_overflows() had s64 a and s64 b as its input args whereas now they are truncated to s32. Thus restore proper types. Also, the case of signed_add32_overflows() is not consistent to signed_sub32_overflows(). Both have s32 as inputs, therefore align the former. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: De4dCr0w Signed-off-by: Daniel Borkmann Reviewed-by: John Fastabend Acked-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 36af69fac591..e7368c5eacb7 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5313,7 +5313,7 @@ static bool signed_add_overflows(s64 a, s64 b) return res < a; } -static bool signed_add32_overflows(s64 a, s64 b) +static bool signed_add32_overflows(s32 a, s32 b) { /* Do the add in u32, where overflow is well-defined */ s32 res = (s32)((u32)a + (u32)b); @@ -5323,7 +5323,7 @@ static bool signed_add32_overflows(s64 a, s64 b) return res < a; } -static bool signed_sub_overflows(s32 a, s32 b) +static bool signed_sub_overflows(s64 a, s64 b) { /* Do the sub in u64, where overflow is well-defined */ s64 res = (s64)((u64)a - (u64)b); @@ -5335,7 +5335,7 @@ static bool signed_sub_overflows(s32 a, s32 b) static bool signed_sub32_overflows(s32 a, s32 b) { - /* Do the sub in u64, where overflow is well-defined */ + /* Do the sub in u32, where overflow is well-defined */ s32 res = (s32)((u32)a - (u32)b); if (b < 0)