(adding some more people, please remember to run get_maintainer.pl to get the full list in the future) On 12/14/18 10:15 AM, Thomas Schoebel-Theuer wrote:
Since commit commit d91525eb8ee6 ("ACPI, EINJ: Enhance error injection tolerance level"), starting with kernel 4.0, the following happens during boot of a specific old hardware: APEI: Can not request [mem 0x0009c2f2-0x0009c2fc] for APEI ERST registers BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81343d8e>] __list_del_entry+0x5c/0x98 PGD 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 1 UID: 0 Comm: swapper/0 Not tainted 4.4.0-ui18344.004-uiabi1-infong-amd64 #1 Hardware name: IBM IBM eServer BladeCenter HS12 -[8028Z5S]-/Server Blade, BIOS -[N1E150AUS-1.11]- 11/04/2010 task: ffff88021fe4e040 ti: ffff88021fe7c000 task.ti: ffff88021fe7c000 RIP: 0010:[<ffffffff81343d8e>] [<ffffffff81343d8e>] __list_del_entry+0x5c/0x98 RSP: 0000:ffff88021fe7fd18 EFLAGS: 00010207 RAX: 0000000000000000 RBX: ffff88021fe7fde0 RCX: ffff88021fe7fde0 RDX: ffffffff819bd040 RSI: dead000000000200 RDI: ffff88021fe7fde0 RBP: ffff88021fe7fd18 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff816ce240 R11: 0000000000000001 R12: ffffffff819bd040 R13: ffff88021fe7fda0 R14: ffff88021d2cd840 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88022fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000019b6000 CR4: 0000000000040670 Stack: ffff88021fe7fd30 ffffffff81343dd7 ffff88021fe7fde0 ffff88021fe7fd58 ffffffff813931c0 ffff88021fe7fda0 ffff88021fe7fe00 ffff88021d2cd840 ffff88021fe7fd70 ffffffff813931e5 00000000ffffffea ffff88021fe7fdf0 Call Trace: [<ffffffff81343dd7>] list_del+0xd/0x25 [<ffffffff813931c0>] apei_res_clean+0x1f/0x37 [<ffffffff813931e5>] apei_resources_fini+0xd/0x19 [<ffffffff81393948>] apei_resources_request+0x24f/0x268 [<ffffffff8139301d>] ? apei_exec_for_each_entry+0x77/0x8e [<ffffffff81b0f729>] ? setup_erst_disable+0x12/0x12 [<ffffffff81b0f816>] erst_init+0xed/0x2ca [<ffffffff810003b2>] ? do_one_initcall+0x8c/0x174 [<ffffffff81b0f729>] ? setup_erst_disable+0x12/0x12 [<ffffffff81b0f729>] ? setup_erst_disable+0x12/0x12 [<ffffffff8100040f>] do_one_initcall+0xe9/0x174 [<ffffffff8105df00>] ? parse_args+0x161/0x296 [<ffffffff81ad6070>] kernel_init_freeable+0x169/0x1f6 [<ffffffff81ad579b>] ? do_early_param+0x88/0x88 [<ffffffff81663202>] ? rest_init+0x79/0x79 [<ffffffff8166320b>] kernel_init+0x9/0xd5 [<ffffffff816683f5>] ret_from_fork+0x55/0x80 [<ffffffff81663202>] ? rest_init+0x79/0x79 Code: 02 00 00 00 00 ad de 48 39 f0 75 1f 49 89 c0 48 c7 c2 38 de 8e 81 be 38 00 00 00 48 c7 c7 13 dd 8e 81 31 c0 e8 94 36 d0 ff eb 3a <48> 8b 30 48 39 fe 74 11 49 89 f0 48 c7 c2 6c de 8e 81 be 3b 00 RIP [<ffffffff81343d8e>] __list_del_entry+0x5c/0x98 RSP <ffff88021fe7fd18> CR2: 0000000000000000 ---[ end trace 3610e544cef27e81 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 Reason is a conditional initialization of variable arch_res, which happens only under a specific precondition. When the condition is false, the variable remains uninitialized. This may later trigger a splat, e.g. when some error path is taken. Solution: do the initialisation unconditionally. Also as a safeguard. Fixes: d91525eb8ee6a622ce476955fe1a2530ade87c83 Signed-off-by: Thomas Schoebel-Theuer <tst@xxxxxxxxxxxxxxxxxx> --- drivers/acpi/apei/apei-base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c index da370e1d31f4..ef931b8a0b11 100644 --- a/drivers/acpi/apei/apei-base.c +++ b/drivers/acpi/apei/apei-base.c @@ -494,8 +494,8 @@ int apei_resources_request(struct apei_resources *resources, if (rc) goto nvs_res_fini;+ apei_resources_init(&arch_res);if (arch_apei_filter_addr) { - apei_resources_init(&arch_res); rc = apei_get_arch_resources(&arch_res); if (rc) goto arch_res_fini;
