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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 4.20 089/105] bpf: don't assume build-id length is always 20 bytes
Date: Tue, 12 Feb 2019 21:33:20 -0500	[thread overview]
Message-ID: <20190213023336.19019-89-sashal@kernel.org> (raw)
In-Reply-To: <20190213023336.19019-1-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 d9e2483669d0..f9df545e92f6 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  2:59 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190213023336.19019-1-sashal@kernel.org>
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 022/105] soc/fsl/qe: fix err handling of ucc_of_parse_tdm Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 032/105] net/mlx4: Get rid of page operation after dma_alloc_coherent Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 034/105] xprtrdma: Double free in rpcrdma_sendctxs_create() Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 035/105] mlxsw: spectrum_acl: Add cleanup after C-TCAM update error condition Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 036/105] mlxsw: spectrum: Add VXLAN dependency for spectrum Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 037/105] selftests: forwarding: Add a test for VLAN deletion Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 038/105] netfilter: nf_tables: fix leaking object reference count Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 043/105] netfilter: nft_flow_offload: Fix reverse route lookup Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 044/105] bpf: correctly set initial window on active Fast Open sender Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 046/105] selftests: bpf: install files tcp_(server|client)*.py Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 047/105] bpf: fix panic in stack_map_get_build_id() on i386 and arm32 Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 049/105] netfilter: nft_flow_offload: fix interaction with vrf slave device Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 053/105] net: stmmac: Fix PCI module removal leak Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 054/105] net: stmmac: dwxgmac2: Only clear interrupts that are active Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 055/105] net: stmmac: Check if CBS is supported before configuring Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 056/105] net: stmmac: Fix the logic of checking if RX Watchdog must be enabled Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 057/105] net: stmmac: Prevent RX starvation in stmmac_napi_poll() Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 058/105] isdn: i4l: isdn_tty: Fix some concurrency double-free bugs Sasha Levin
2019-02-13  2:32 ` [PATCH AUTOSEL 4.20 065/105] netfilter: nft_flow_offload: fix checking method of conntrack helper Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 070/105] vhost: return EINVAL if iovecs size does not match the message size Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 071/105] vhost/scsi: Use copy_to_iter() to send control queue response Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 072/105] xsk: Check if a queue exists during umem setup Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 073/105] selftests/bpf: install with_tunnels.sh for test_flow_dissector.sh Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 074/105] samples/bpf: workaround clang asm goto compilation errors Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 075/105] SUNRPC: Ensure rq_bytes_sent is reset before request transmission Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 076/105] SUNRPC: Ensure we respect the RPCSEC_GSS sequence number limit Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 080/105] net: phy: micrel: set soft_reset callback to genphy_soft_reset for KSZ9031 Sasha Levin
2019-02-13  2:33 ` Sasha Levin [this message]
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 090/105] bpf: zero out build_id for BPF_STACK_BUILD_ID_IP Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 091/105] selftests/bpf: retry tests that expect build-id Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 092/105] atm: he: fix sign-extension overflow on large shift Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 095/105] bpf: bpf_setsockopt: reset sock dst on SO_MARK changes Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 096/105] bpf: fix SO_MAX_PACING_RATE to support TCP internal pacing Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 097/105] dpaa_eth: NETIF_F_LLTX requires to do our own update of trans_start Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 098/105] mlxsw: pci: Return error on PCI reset timeout Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 099/105] net: bridge: Mark FDB entries that were added by user as such Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 100/105] mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 101/105] selftests: forwarding: Add a test case for externally learned FDB entries Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 103/105] net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 104/105] net/mlx5e: Fix wrong (zero) TX drop counter indication for representor Sasha Levin
2019-02-13  2:33 ` [PATCH AUTOSEL 4.20 105/105] isdn: avm: Fix string plus integer warning from Clang Sasha Levin

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