[CCing the regression list, as it should be in the loop for regressions: https://docs.kernel.org/admin-guide/reporting-regressions.html] [TLDR: I'm adding this report to the list of tracked Linux kernel regressions; all text you find below is based on a few templates paragraphs you might have encountered already in similar form. See link in footer if these mails annoy you.] On 07.01.23 23:04, dai.ngo@xxxxxxxxxx wrote: > Hi, > > This is a regression in 6.2.0-rc1. > > The problem can be reproduced with a simple test: > . client mounts server's export using 4.1 > . client cats a file on server's export > . on server stop nfs-server service > > Bisect points to commit ac3a2585f018 (nfsd: rework refcounting in > filecache) Thanks for the report. To be sure the issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression tracking bot: #regzbot ^introduced ac3a2585f018 #regzbot title NFSD: refcount_t: underflow; use-after-free from nfsd_file_free #regzbot ignore-activity This isn't a regression? This issue or a fix for it are already discussed somewhere else? It was fixed already? You want to clarify when the regression started to happen? Or point out I got the title or something else totally wrong? Then just reply and tell me -- ideally while also telling regzbot about it, as explained by the page listed in the footer of this mail. Developers: When fixing the issue, remember to add 'Link:' tags pointing to the report (the parent of this mail). See page linked in footer for details. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr That page also explains what to do if mails like this annoy you. > Jan 7 12:15:56 nfsvmf14 kernel: ------------[ cut here ]------------ > Jan 7 12:15:56 nfsvmf14 kernel: refcount_t: underflow; use-after-free. > Jan 7 12:15:56 nfsvmf14 kernel: WARNING: CPU: 0 PID: 10420 at > lib/refcount.c:28 refcount_warn_saturate+0xb3/0x100 > Jan 7 12:15:56 nfsvmf14 kernel: Modules linked in: rpcsec_gss_krb5 > btrfs blake2b_generic xor raid6_pq zstd_compress intel_powerclamp sg > nfsd nfs_acl auth_rpcgss lockd grace sunrpc xfs dm_mirror dm_region_hash > dm_log dm_mod > Jan 7 12:15:56 nfsvmf14 kernel: CPU: 0 PID: 10420 Comm: rpc.nfsd Kdump: > loaded Tainted: G W 6.2.0-rc1 #1 > Jan 7 12:15:56 nfsvmf14 kernel: Hardware name: innotek GmbH > VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 > Jan 7 12:15:56 nfsvmf14 kernel: RIP: > 0010:refcount_warn_saturate+0xb3/0x100 > Jan 7 12:15:56 nfsvmf14 kernel: Code: 01 01 e8 3f 21 65 00 0f 0b c3 cc > cc cc cc 80 3d f5 d1 4a 01 00 75 5b 48 c7 c7 c3 4b 22 82 c6 05 e5 d1 4a > 01 01 e8 1c 21 65 00 <0f> 0b c3 cc cc cc cc 80 3d d1 d1 4a 01 00 75 38 > 48 c7 c7 eb 4b 22 > Jan 7 12:15:56 nfsvmf14 kernel: RSP: 0018:ffffc9000078fc98 EFLAGS: > 00010282 > Jan 7 12:15:56 nfsvmf14 kernel: RAX: 0000000000000000 RBX: > ffff88810e8a9930 RCX: 0000000000000027 > Jan 7 12:15:56 nfsvmf14 kernel: RDX: 00000000ffff7fff RSI: > 0000000000000003 RDI: ffff888217c1c640 > Jan 7 12:15:56 nfsvmf14 kernel: RBP: ffff88810cbd7870 R08: > 0000000000000000 R09: ffffffff827d9f88 > Jan 7 12:15:56 nfsvmf14 kernel: R10: 00000000756f6366 R11: > 0000000063666572 R12: ffff888111c9c000 > Jan 7 12:15:56 nfsvmf14 kernel: R13: ffff88810fb5fa00 R14: > ffff88810f980058 R15: ffff88810e6d68b0 > Jan 7 12:15:56 nfsvmf14 kernel: FS: 00007fa614d16840(0000) > GS:ffff888217c00000(0000) knlGS:0000000000000000 > Jan 7 12:15:56 nfsvmf14 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: > 0000000080050033 > Jan 7 12:15:56 nfsvmf14 kernel: CR2: 0000559a53e66908 CR3: > 0000000110c72000 CR4: 00000000000406f0 > Jan 7 12:15:56 nfsvmf14 kernel: Call Trace: > Jan 7 12:15:56 nfsvmf14 kernel: <TASK> > Jan 7 12:15:56 nfsvmf14 kernel: > __refcount_sub_and_test.constprop.0+0x2b/0x36 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfsd_file_free+0x119/0x182 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: destroy_unhashed_deleg+0x65/0x8e [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: __destroy_client+0xc3/0x1ea [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfs4_state_shutdown_net+0x12c/0x236 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfsd_shutdown_net+0x35/0x58 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfsd_put+0xbf/0x117 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfsd_svc+0x2d0/0x2f2 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: write_threads+0x6d/0xb9 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: ? write_versions+0x333/0x333 [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: nfsctl_transaction_write+0x4f/0x6b [nfsd] > Jan 7 12:15:56 nfsvmf14 kernel: vfs_write+0xdb/0x1e5 > Jan 7 12:15:56 nfsvmf14 kernel: ? kmem_cache_free+0xf1/0x186 > Jan 7 12:15:56 nfsvmf14 kernel: ? do_sys_openat2+0xcd/0xf5 > Jan 7 12:15:56 nfsvmf14 kernel: ? __fget_light+0x2d/0x78 > Jan 7 12:15:56 nfsvmf14 kernel: ksys_write+0x76/0xc3 > Jan 7 12:15:56 nfsvmf14 kernel: do_syscall_64+0x56/0x71 > Jan 7 12:15:56 nfsvmf14 kernel: entry_SYSCALL_64_after_hwframe+0x63/0xcd > Jan 7 12:15:56 nfsvmf14 kernel: RIP: 0033:0x7fa6142efa00 > Jan 7 12:15:56 nfsvmf14 kernel: Code: 73 01 c3 48 8b 0d 70 74 2d 00 f7 > d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d bd d5 2d 00 00 75 10 > b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee cb > 01 00 48 89 04 24 > Jan 7 12:15:56 nfsvmf14 kernel: RSP: 002b:00007ffc79bf4748 EFLAGS: > 00000246 ORIG_RAX: 0000000000000001 > Jan 7 12:15:56 nfsvmf14 kernel: RAX: ffffffffffffffda RBX: > 0000000000000003 RCX: 00007fa6142efa00 > Jan 7 12:15:56 nfsvmf14 kernel: RDX: 0000000000000002 RSI: > 000055d4cb8093e0 RDI: 0000000000000003 > Jan 7 12:15:56 nfsvmf14 kernel: RBP: 000055d4cb8093e0 R08: > 0000000000000000 R09: 00007fa61424d2cd > Jan 7 12:15:56 nfsvmf14 kernel: R10: 0000000000000004 R11: > 0000000000000246 R12: 0000000000000000 > Jan 7 12:15:56 nfsvmf14 kernel: R13: 0000000000000000 R14: > 0000000000000000 R15: 000000000000001f > Jan 7 12:15:56 nfsvmf14 kernel: </TASK> > Jan 7 12:15:56 nfsvmf14 kernel: ---[ end trace 0000000000000000 ]--- >
