Bug#920177: linux-image-4.19.0-2-rt-amd64-unsigned: BUG while removing the sunrpc module
Control: tags -1 + moreinfo
On Tue, Jan 22, 2019 at 12:20:38PM +0100, Laurent Bonnaud wrote:
> Subject: linux-image-4.19.0-2-rt-amd64-unsigned: BUG
> Package: src:linux
> Version: 4.19.16-1
> Severity: normal
>
>
> Dear Maintainer,
>
> I was trying to remove the sunrpc module from the kernel and got the following BUG and backtrace.
>
> Note that the kernel is tainted because of this previous error that is unrelated:
>
> [ 1.514708] button: module verification failed: signature and/or required key missing - tainting kernel
>
> [ 204.858131] RPC: Unregistered named UNIX socket transport module.
> [ 204.858134] RPC: Unregistered udp transport module.
> [ 204.858136] RPC: Unregistered tcp transport module.
> [ 204.858137] RPC: Unregistered tcp NFSv4.1 backchannel transport module.
> [ 204.859248] =============================================================================
> [ 204.859251] BUG rpc_inode_cache (Tainted: G E ): Objects remaining in rpc_inode_cache on __kmem_cache_shutdown()
> [ 204.859251] -----------------------------------------------------------------------------
>
> [ 204.859252] Disabling lock debugging due to kernel taint
> [ 204.859255] INFO: Slab 0x00000000006c197c objects=18 used=13 fp=0x00000000a584567e flags=0x17fffc000008100
> [ 204.859259] CPU: 0 PID: 3633 Comm: rmmod Tainted: G B E 4.19.0-2-rt-amd64 #1 Debian 4.19.16-1
> [ 204.859260] Hardware name: Dell Inc. OptiPlex 7010/0KRC95, BIOS A29 06/28/2018
> [ 204.859261] Call Trace:
> [ 204.859269] dump_stack+0x5c/0x80
> [ 204.859273] slab_err+0xb0/0xd4
> [ 204.859277] ? cpumask_next+0x16/0x20
> [ 204.859279] ? flush_all+0x66/0x100
> [ 204.859282] __kmem_cache_shutdown.cold.103+0x1c/0x26
> [ 204.859287] shutdown_cache+0x15/0x1c0
> [ 204.859290] kmem_cache_destroy+0x216/0x240
> [ 204.859316] unregister_rpc_pipefs+0x16/0x30 [sunrpc]
> [ 204.859334] cleanup_sunrpc+0x1e/0x39 [sunrpc]
> [ 204.859337] __x64_sys_delete_module+0x190/0x2c0
> [ 204.859341] do_syscall_64+0x53/0x100
> [ 204.859346] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> [ 204.859349] RIP: 0033:0x7f43fb8a00f7
> [ 204.859351] Code: 73 01 c3 48 8b 0d 99 0d 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 69 0d 0c 00 f7 d8 64 89 01 48
> [ 204.859354] RSP: 002b:00007ffc4236d208 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
> [ 204.859356] RAX: ffffffffffffffda RBX: 000055a14f7eb220 RCX: 00007f43fb8a00f7
> [ 204.859357] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055a14f7eb288
> [ 204.859358] RBP: 0000000000000000 R08: 00007ffc4236c181 R09: 0000000000000000
> [ 204.859359] R10: 00007f43fb911ae0 R11: 0000000000000206 R12: 00007ffc4236d430
> [ 204.859360] R13: 00007ffc4236ec4b R14: 000055a14f7ea010 R15: 000055a14f7eb220
> [ 204.859363] kmem_cache_destroy rpc_inode_cache: Slab cache still has objects
> [ 204.859621] CPU: 0 PID: 3633 Comm: rmmod Tainted: G B E 4.19.0-2-rt-amd64 #1 Debian 4.19.16-1
> [ 204.859622] Hardware name: Dell Inc. OptiPlex 7010/0KRC95, BIOS A29 06/28/2018
> [ 204.859623] Call Trace:
> [ 204.859626] dump_stack+0x5c/0x80
> [ 204.859629] kmem_cache_destroy+0x233/0x240
> [ 204.859647] unregister_rpc_pipefs+0x16/0x30 [sunrpc]
> [ 204.859664] cleanup_sunrpc+0x1e/0x39 [sunrpc]
> [ 204.859666] __x64_sys_delete_module+0x190/0x2c0
> [ 204.859670] do_syscall_64+0x53/0x100
> [ 204.859673] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> [ 204.859675] RIP: 0033:0x7f43fb8a00f7
> [ 204.859677] Code: 73 01 c3 48 8b 0d 99 0d 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 69 0d 0c 00 f7 d8 64 89 01 48
> [ 204.859678] RSP: 002b:00007ffc4236d208 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
> [ 204.859679] RAX: ffffffffffffffda RBX: 000055a14f7eb220 RCX: 00007f43fb8a00f7
> [ 204.859680] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055a14f7eb288
> [ 204.859681] RBP: 0000000000000000 R08: 00007ffc4236c181 R09: 0000000000000000
> [ 204.859682] R10: 00007f43fb911ae0 R11: 0000000000000206 R12: 00007ffc4236d430
> [ 204.859683] R13: 00007ffc4236ec4b R14: 000055a14f7ea010 R15: 000055a14f7eb220
This was not while trying to force unload and sunrpc was really not
anymore in use?
Recently there was a fix for f1442d6349a2 ("sunrpc: fix refcount leak for rpc auth modules")
https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t
That fix from 5.12-rc4 went into 4.19.183 (not yet available for
buster, but working on) and 5.10.26.
Can you reproduce the issue using 5.10.40-1 from unstable?
Regards,
Salvatore
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