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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Stanislav Fomichev <sdf@google.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 70/83] bpf: don't assume build-id length is always 20 bytes
Date: Tue, 12 Feb 2019 21:36:48 -0500	[thread overview]
Message-ID: <20190213023701.20286-70-sashal@kernel.org> (raw)
In-Reply-To: <20190213023701.20286-1-sashal@kernel.org>

From: Stanislav Fomichev <sdf@google.com>

[ Upstream commit 0b698005a9d11c0e91141ec11a2c4918a129f703 ]

Build-id length is not fixed to 20, it can be (`man ld` /--build-id):
  * 128-bit (uuid)
  * 160-bit (sha1)
  * any length specified in ld --build-id=0xhexstring

To fix the issue of missing BPF_STACK_BUILD_ID_VALID for shorter build-ids,
assume that build-id is somewhere in the range of 1 .. 20.
Set the remaining bytes to zero.

v2:
* don't introduce new "len = min(BPF_BUILD_ID_SIZE, nhdr->n_descsz)",
  we already know that nhdr->n_descsz <= BPF_BUILD_ID_SIZE if we enter
  this 'if' condition

Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address")
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/bpf/stackmap.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index e50ef5bca421..98ad9dc3587a 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -180,11 +180,14 @@ static inline int stack_map_parse_build_id(void *page_addr,
 
 		if (nhdr->n_type == BPF_BUILD_ID &&
 		    nhdr->n_namesz == sizeof("GNU") &&
-		    nhdr->n_descsz == BPF_BUILD_ID_SIZE) {
+		    nhdr->n_descsz > 0 &&
+		    nhdr->n_descsz <= BPF_BUILD_ID_SIZE) {
 			memcpy(build_id,
 			       note_start + note_offs +
 			       ALIGN(sizeof("GNU"), 4) + sizeof(Elf32_Nhdr),
-			       BPF_BUILD_ID_SIZE);
+			       nhdr->n_descsz);
+			memset(build_id + nhdr->n_descsz, 0,
+			       BPF_BUILD_ID_SIZE - nhdr->n_descsz);
 			return 0;
 		}
 		new_offs = note_offs + sizeof(Elf32_Nhdr) +
-- 
2.19.1


  parent reply	other threads:[~2019-02-13  2:51 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190213023701.20286-1-sashal@kernel.org>
2019-02-13  2:35 ` [PATCH AUTOSEL 4.19 21/83] qed: Fix qed_chain_set_prod() for PBL chains with non power of 2 page count Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 22/83] qed: Fix qed_ll2_post_rx_buffer_notify_fw() by adding a write memory barrier Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 23/83] net: hns: Fix use after free identified by SLUB debug Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 24/83] bpf: Fix [::] -> [::1] rewrite in sys_sendmsg Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 25/83] selftests/bpf: Test [::] -> [::1] rewrite in sys_sendmsg in test_sock_addr Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 27/83] net/mlx4: Get rid of page operation after dma_alloc_coherent Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 29/83] xprtrdma: Double free in rpcrdma_sendctxs_create() Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 30/83] mlxsw: spectrum_acl: Add cleanup after C-TCAM update error condition Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 31/83] selftests: forwarding: Add a test for VLAN deletion Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 32/83] netfilter: nf_tables: fix leaking object reference count Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 37/83] netfilter: nft_flow_offload: Fix reverse route lookup Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 38/83] bpf: correctly set initial window on active Fast Open sender Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 40/83] bpf: fix panic in stack_map_get_build_id() on i386 and arm32 Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 41/83] netfilter: nft_flow_offload: fix interaction with vrf slave device Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 45/83] net: stmmac: Fix PCI module removal leak Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 46/83] net: stmmac: dwxgmac2: Only clear interrupts that are active Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 47/83] net: stmmac: Check if CBS is supported before configuring Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 48/83] net: stmmac: Fix the logic of checking if RX Watchdog must be enabled Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 49/83] net: stmmac: Prevent RX starvation in stmmac_napi_poll() Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 50/83] isdn: i4l: isdn_tty: Fix some concurrency double-free bugs Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 56/83] netfilter: nft_flow_offload: fix checking method of conntrack helper Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 61/83] vhost: return EINVAL if iovecs size does not match the message size Sasha Levin
2019-02-13  2:36 ` Sasha Levin [this message]
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 71/83] bpf: zero out build_id for BPF_STACK_BUILD_ID_IP Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 72/83] selftests/bpf: retry tests that expect build-id Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 73/83] atm: he: fix sign-extension overflow on large shift Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 76/83] bpf: bpf_setsockopt: reset sock dst on SO_MARK changes Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 77/83] dpaa_eth: NETIF_F_LLTX requires to do our own update of trans_start Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 78/83] mlxsw: pci: Return error on PCI reset timeout Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 79/83] net: bridge: Mark FDB entries that were added by user as such Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 80/83] mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky Sasha Levin
2019-02-13  2:36 ` [PATCH AUTOSEL 4.19 81/83] selftests: forwarding: Add a test case for externally learned FDB entries Sasha Levin
2019-02-13  2:37 ` [PATCH AUTOSEL 4.19 82/83] net/mlx5e: Fix wrong (zero) TX drop counter indication for representor Sasha Levin
2019-02-13  2:37 ` [PATCH AUTOSEL 4.19 83/83] isdn: avm: Fix string plus integer warning from Clang Sasha Levin

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