Overall, we encountered a warning [1] that can be triggered by running the
selftest I provided.
sockmap works by replacing sk_data_ready, recvmsg, sendmsg operations and
implementing fast socket-level forwarding logic:
1. Users can obtain file descriptors through userspace socket()/accept()
interfaces, then call BPF syscall to perform these replacements.
2. Users can also use the bpf_sock_hash_update helper (in sockops programs)
to replace handlers when TCP connections enter ESTABLISHED state
(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB/BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB)
However, when combined with MPTCP, an issue arises: MPTCP creates subflow
sk's and performs TCP handshakes, so the BPF program obtains subflow sk's
and may incorrectly replace their sk_prot. We need to reject such
operations. In patch 1, we set psock_update_sk_prot to NULL in the
subflow's custom sk_prot.
Additionally, if the server's listening socket has MPTCP enabled and the
client's TCP also uses MPTCP, we should allow the combination of subflow
and sockmap. This is because the latest Golang programs have enabled MPTCP
for listening sockets by default [2]. For programs already using sockmap,
upgrading Golang should not cause sockmap functionality to fail.
Patch 2 prevents the panic from occurring.
Despite these patches fixing stream corruption, users of sockmap must set
GODEBUG=multipathtcp=0 to disable MPTCP until sockmap fully supports it.
[1] truncated warning:
------------[ cut here ]------------
BUG: kernel NULL pointer dereference, address: 00000000000004bb
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 400 Comm: test_progs Not tainted 6.1.0+ #16
RIP: 0010:mptcp_stream_accept (./include/linux/list.h:88 net/mptcp/protocol.c:3719)
RSP: 0018:ffffc90000ef3cf0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880089dcc58
RDX: 0000000000000003 RSI: 0000002c000000b0 RDI: 0000000000000000
RBP: ffffc90000ef3d38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880089dc600
R13: ffff88800b859e00 R14: ffff88800638c680 R15: 0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000004bb CR3: 000000000b8e8006 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? apparmor_socket_accept (security/apparmor/lsm.c:966)
do_accept (net/socket.c:1856)
__sys_accept4 (net/socket.c:1897 net/socket.c:1927)
__x64_sys_accept (net/socket.c:1941)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[2]: https://go-review.googlesource.com/c/go/+/607715
Jiayuan Chen (2):
mptcp: disallow MPTCP subflows from sockmap
net,mptcp: fix proto fallback detection with BPF
net/mptcp/protocol.c | 5 +++--
net/mptcp/subflow.c | 8 ++++++++
2 files changed, 11 insertions(+), 2 deletions(-)
--
2.43.0
The mmio regmap allocated during probe is never freed.
Switch to using the device managed allocator so that the regmap is
released on probe failures (e.g. probe deferral) and on driver unbind.
Fixes: a250cd4c1901 ("clk: keystone: syscon-clk: Do not use syscon helper to build regmap")
Cc: stable(a)vger.kernel.org # 6.15
Cc: Andrew Davis <afd(a)ti.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/clk/keystone/syscon-clk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/keystone/syscon-clk.c b/drivers/clk/keystone/syscon-clk.c
index c509929da854..ecf180a7949c 100644
--- a/drivers/clk/keystone/syscon-clk.c
+++ b/drivers/clk/keystone/syscon-clk.c
@@ -129,7 +129,7 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
if (IS_ERR(base))
return PTR_ERR(base);
- regmap = regmap_init_mmio(dev, base, &ti_syscon_regmap_cfg);
+ regmap = devm_regmap_init_mmio(dev, base, &ti_syscon_regmap_cfg);
if (IS_ERR(regmap))
return dev_err_probe(dev, PTR_ERR(regmap),
"failed to get regmap\n");
--
2.51.2
Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with
__counted_by") annotated the hws member of 'struct clk_hw_onecell_data'
with __counted_by, which informs the bounds sanitizer (UBSAN_BOUNDS)
about the number of elements in .hws[], so that it can warn when .hws[]
is accessed out of bounds. As noted in that change, the __counted_by
member must be initialized with the number of elements before the first
array access happens, otherwise there will be a warning from each access
prior to the initialization because the number of elements is zero. This
occurs in exynos_clkout_probe() due to .num being assigned after .hws[]
has been accessed:
UBSAN: array-index-out-of-bounds in drivers/clk/samsung/clk-exynos-clkout.c:178:18
index 0 is out of range for type 'clk_hw *[*]'
Move the .num initialization to before the first access of .hws[],
clearing up the warning.
Cc: stable(a)vger.kernel.org
Fixes: f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by")
Reported-by: Jochen Sprickerhof <jochen(a)sprickerhof.de>
Closes: https://lore.kernel.org/aSIYDN5eyKFKoXKL@eldamar.lan/
Tested-by: Jochen Sprickerhof <jochen(a)sprickerhof.de>
Signed-off-by: Nathan Chancellor <nathan(a)kernel.org>
---
drivers/clk/samsung/clk-exynos-clkout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/samsung/clk-exynos-clkout.c b/drivers/clk/samsung/clk-exynos-clkout.c
index 5f1a4f5e2e59..5b21025338bd 100644
--- a/drivers/clk/samsung/clk-exynos-clkout.c
+++ b/drivers/clk/samsung/clk-exynos-clkout.c
@@ -175,6 +175,7 @@ static int exynos_clkout_probe(struct platform_device *pdev)
clkout->mux.shift = EXYNOS_CLKOUT_MUX_SHIFT;
clkout->mux.lock = &clkout->slock;
+ clkout->data.num = EXYNOS_CLKOUT_NR_CLKS;
clkout->data.hws[0] = clk_hw_register_composite(NULL, "clkout",
parent_names, parent_count, &clkout->mux.hw,
&clk_mux_ops, NULL, NULL, &clkout->gate.hw,
@@ -185,7 +186,6 @@ static int exynos_clkout_probe(struct platform_device *pdev)
goto err_unmap;
}
- clkout->data.num = EXYNOS_CLKOUT_NR_CLKS;
ret = of_clk_add_hw_provider(clkout->np, of_clk_hw_onecell_get, &clkout->data);
if (ret)
goto err_clk_unreg;
---
base-commit: b6430552c8cd95e90bb842ce2f421e7a5381859f
change-id: 20251124-exynos-clkout-fix-ubsan-bounds-error-93071375ec78
Best regards,
--
Nathan Chancellor <nathan(a)kernel.org>