[<prev] [next>] [day] [month] [year] [list]
Message-Id: <20250407-null-ec-parent-v1-1-f7dda62d3110@igalia.com>
Date: Mon, 07 Apr 2025 17:33:34 -0300
From: Thadeu Lima de Souza Cascardo <cascardo@...lia.com>
To: Andi Shyti <andi.shyti@...nel.org>, Benson Leung <bleung@...omium.org>,
Guenter Roeck <groeck@...omium.org>, Doug Anderson <dianders@...omium.org>,
Vincent Palatin <vpalatin@...omium.org>, Simon Glass <sjg@...omium.org>,
Lee Jones <lee@...nel.org>, Wolfram Sang <wsa@...nel.org>
Cc: linux-i2c@...r.kernel.org, chrome-platform@...ts.linux.dev,
linux-kernel@...r.kernel.org, kernel-dev@...lia.com,
Thadeu Lima de Souza Cascardo <cascardo@...lia.com>
Subject: [PATCH] i2c: cros-ec-tunnel: defer probe if parent EC is not
present
When i2c-cros-ec-tunnel and the EC driver are built-in, the EC parent
device will not be found, leading to NULL pointer dereference.
That can also be reproduced by unbinding the controller driver and then
loading i2c-cros-ec-tunnel module (or binding the device).
[ 271.991245] BUG: kernel NULL pointer dereference, address: 0000000000000058
[ 271.998215] #PF: supervisor read access in kernel mode
[ 272.003351] #PF: error_code(0x0000) - not-present page
[ 272.008485] PGD 0 P4D 0
[ 272.011022] Oops: Oops: 0000 [#1] SMP NOPTI
[ 272.015207] CPU: 0 UID: 0 PID: 3859 Comm: insmod Tainted: G S 6.15.0-rc1-00004-g44722359ed83 #30 PREEMPT(full) 3c7fb39a552e7d949de2ad921a7d6588d3a4fdc5
[ 272.030312] Tainted: [S]=CPU_OUT_OF_SPEC
[ 272.034233] Hardware name: HP Berknip/Berknip, BIOS Google_Berknip.13434.356.0 05/17/2021
[ 272.042400] RIP: 0010:ec_i2c_probe+0x2b/0x1c0 [i2c_cros_ec_tunnel]
[ 272.048577] Code: 1f 44 00 00 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 06 a0 6c e7 48 89 44 24 08 4c 8d 7f 10 48 8b 47 50 4c 8b 60 78 <49> 83 7c 24 58 00 0f 84 2f 01 00 00 48 89 fb be 30 06 00 00 4c 9
[ 272.067317] RSP: 0018:ffffa32082a03940 EFLAGS: 00010282
[ 272.072541] RAX: ffff969580b6a810 RBX: ffff969580b68c10 RCX: 0000000000000000
[ 272.079672] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff969580b68c00
[ 272.086804] RBP: 00000000fffffdfb R08: 0000000000000000 R09: 0000000000000000
[ 272.093936] R10: 0000000000000000 R11: ffffffffc0600000 R12: 0000000000000000
[ 272.101067] R13: ffffffffa666fbb8 R14: ffffffffc05b5528 R15: ffff969580b68c10
[ 272.108198] FS: 00007b930906fc40(0000) GS:ffff969603149000(0000) knlGS:0000000000000000
[ 272.116282] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 272.122024] CR2: 0000000000000058 CR3: 000000012631c000 CR4: 00000000003506f0
[ 272.129155] Call Trace:
[ 272.131606] <TASK>
[ 272.133709] ? acpi_dev_pm_attach+0xdd/0x110
[ 272.137985] platform_probe+0x69/0xa0
[ 272.141652] really_probe+0x152/0x310
[ 272.145318] __driver_probe_device+0x77/0x110
[ 272.149678] driver_probe_device+0x1e/0x190
[ 272.153864] __driver_attach+0x10b/0x1e0
[ 272.157790] ? driver_attach+0x20/0x20
[ 272.161542] bus_for_each_dev+0x107/0x150
[ 272.165553] bus_add_driver+0x15d/0x270
[ 272.169392] driver_register+0x65/0x110
[ 272.173232] ? cleanup_module+0xa80/0xa80 [i2c_cros_ec_tunnel 3a00532f3f4af4a9eade753f86b0f8dd4e4e5698]
[ 272.182617] do_one_initcall+0x110/0x350
[ 272.186543] ? security_kernfs_init_security+0x49/0xd0
[ 272.191682] ? __kernfs_new_node+0x1b9/0x240
[ 272.195954] ? security_kernfs_init_security+0x49/0xd0
[ 272.201093] ? __kernfs_new_node+0x1b9/0x240
[ 272.205365] ? kernfs_link_sibling+0x105/0x130
[ 272.209810] ? kernfs_next_descendant_post+0x1c/0xa0
[ 272.214773] ? kernfs_activate+0x57/0x70
[ 272.218699] ? kernfs_add_one+0x118/0x160
[ 272.222710] ? __kernfs_create_file+0x71/0xa0
[ 272.227069] ? sysfs_add_bin_file_mode_ns+0xd6/0x110
[ 272.232033] ? internal_create_group+0x453/0x4a0
[ 272.236651] ? __vunmap_range_noflush+0x214/0x2d0
[ 272.241355] ? __free_frozen_pages+0x1dc/0x420
[ 272.245799] ? free_vmap_area_noflush+0x10a/0x1c0
[ 272.250505] ? load_module+0x1509/0x16f0
[ 272.254431] do_init_module+0x60/0x230
[ 272.258181] __se_sys_finit_module+0x27a/0x370
[ 272.262627] do_syscall_64+0x6a/0xf0
[ 272.266206] ? do_syscall_64+0x76/0xf0
[ 272.269956] ? irqentry_exit_to_user_mode+0x79/0x90
[ 272.274836] entry_SYSCALL_64_after_hwframe+0x55/0x5d
[ 272.279887] RIP: 0033:0x7b9309168d39
[ 272.283466] Code: 5b 41 5c 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d af 40 0c 00 f7 d8 64 89 01 8
[ 272.302210] RSP: 002b:00007fff50f1a288 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 272.309774] RAX: ffffffffffffffda RBX: 000058bf9b50f6d0 RCX: 00007b9309168d39
[ 272.316905] RDX: 0000000000000000 RSI: 000058bf6c103a77 RDI: 0000000000000003
[ 272.324036] RBP: 00007fff50f1a2e0 R08: 00007fff50f19218 R09: 0000000021ec4150
[ 272.331166] R10: 000058bf9b50f7f0 R11: 0000000000000246 R12: 0000000000000000
[ 272.338296] R13: 00000000fffffffe R14: 0000000000000000 R15: 000058bf6c103a77
[ 272.345428] </TASK>
[ 272.347617] Modules linked in: i2c_cros_ec_tunnel(+)
[ 272.364585] gsmi: Log Shutdown Reason 0x03
Returning -EPROBE_DEFER will allow the device to be bound once the
controller is bound, in the case of built-in drivers.
Fixes: 9d230c9e4f4e ("i2c: ChromeOS EC tunnel driver")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@...lia.com>
---
drivers/i2c/busses/i2c-cros-ec-tunnel.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
index 43bf90d90eebabe88af2d6a32a299da9175799e9..208ce4f9e782cdc5e08a5c91ccc8ddfeb4c6ef04 100644
--- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c
+++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
@@ -247,6 +247,9 @@ static int ec_i2c_probe(struct platform_device *pdev)
u32 remote_bus;
int err;
+ if (!ec)
+ return dev_err_probe(dev, -EPROBE_DEFER, "couldn't find parent EC device\n");
+
if (!ec->cmd_xfer) {
dev_err(dev, "Missing sendrecv\n");
return -EINVAL;
---
base-commit: abc16e78abb442bfbfb6497712d64500a6ed8c2f
change-id: 20250331-null-ec-parent-37018ef84733
Best regards,
--
Thadeu Lima de Souza Cascardo <cascardo@...lia.com>
Powered by blists - more mailing lists