On Tue, Aug 30, 2022 at 1:49 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > On Tue, 2022-08-30 at 13:14 -0400, Olga Kornievskaia wrote: > > Hi folks, > > > > Is this a known nfsd kernel oops in 6.0-rc1. Was running xfstests on > > pre-rhel-9.1 client against 6.0-rc1 server when it panic-ed. > > > > [ 5554.769159] BUG: KASAN: null-ptr-deref in kernel_sendpage+0x60/0x220 > > [ 5554.770526] Read of size 8 at addr 0000000000000008 by task nfsd/2590 > > [ 5554.771899] > > No, I haven't seen this one. I'm guessing the page pointer passed to > kernel_sendpage was probably NULL, so this may be a case where something > walked off the end of the rq_pages array? > > Beyond that I can't tell much from just this stack trace. It might be > nice to see what line of code kernel_sendpage+0x60 refers to on your > kernel. After getting debug symbols this is what gdb told me... (gdb) l *(kernel_sendpage+0x60) 0xffffffff81cbd570 is in kernel_sendpage (./include/linux/page-flags.h:487). 482 TESTCLEARFLAG(LRU, lru, PF_HEAD) 483 PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) 484 TESTCLEARFLAG(Active, active, PF_HEAD) 485 PAGEFLAG(Workingset, workingset, PF_HEAD) 486 TESTCLEARFLAG(Workingset, workingset, PF_HEAD) 487 __PAGEFLAG(Slab, slab, PF_NO_TAIL) 488 __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) 489 PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ 490 491 /* Xen */ I'm unable to complete a git bisect. Could somebody suggest what to do when a git bisect midpoint results in an unbootable kernel? I can't "skip" this point can I? I'm not sure if marking it "bad" makes sense since it's not relevant to the actual problem. However, what I believe I can determine is that NFSD changes are not to blame because I have a git bisect point which lead to a failure and which didn't have nfsd changes yet (see git bisect log below) [aglo@ipa84 linux-nfs]$ git bisect log git bisect start # bad: [632de0656c63f11f3700d1a03cacfdb4b85ae98f] NFSD enforce filehandle check for source file in COPY git bisect bad 632de0656c63f11f3700d1a03cacfdb4b85ae98f # good: [3d7cb6b04c3f3115719235cc6866b10326de34cd] Linux 5.19 git bisect good 3d7cb6b04c3f3115719235cc6866b10326de34cd # good: [b44f2fd87919b5ae6e1756d4c7ba2cbba22238e1] Merge tag 'drm-next-2022-08-03' of git://anongit.freedesktop.org/drm/drm git bisect good b44f2fd87919b5ae6e1756d4c7ba2cbba22238e1 # good: [6614a3c3164a5df2b54abb0b3559f51041cf705b] Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm git bisect good 6614a3c3164a5df2b54abb0b3559f51041cf705b # good: [eb5699ba31558bdb2cee6ebde3d0a68091e47dce] Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm git bisect good eb5699ba31558bdb2cee6ebde3d0a68091e47dce # bad: [5e2e7383b57fa03ec2b00c82bb7f49a4a707c1f7] Merge tag 'pinctrl-v6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl git bisect bad 5e2e7383b57fa03ec2b00c82bb7f49a4a707c1f7 # good: [507f811f205c17fd6f64e8d34d4bf91cd01b07a2] Merge tag 'pm-5.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm git bisect good 507f811f205c17fd6f64e8d34d4bf91cd01b07a2 # bad: [e394ff83bbca1c72427b1feb5c6b9d4dad832f01] Merge tag 'nfsd-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux git bisect bad e394ff83bbca1c72427b1feb5c6b9d4dad832f01 # bad: [f30adc0d332fdfe5315cb98bd6a7ff0d5cf2aa38] Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs git bisect bad f30adc0d332fdfe5315cb98bd6a7ff0d5cf2aa38 # bad: [8447d0e75099eb54eea9306c2d43ecfc956d09ed] remoteproc: qcom_q6v5_pas: Do not fail if regulators are not found git bisect bad 8447d0e75099eb54eea9306c2d43ecfc956d09ed "Merge tag nfsd-6.0" was bad but so was "Merge tag 'pull-work.iov_iter-rebased'" which is before that. So something else broke something in the kernel which is affecting NFSD. Again if somebody could suggest how I could keep git bisecting where I get non-bootable kernel I could continue... > > > [ 5554.772249] CPU: 1 PID: 2590 Comm: nfsd Not tainted 6.0.0-rc1+ #84 > > [ 5554.773575] Hardware name: VMware, Inc. VMware Virtual > > Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 > > [ 5554.775952] Call Trace: > > [ 5554.776500] <TASK> > > [ 5554.776977] dump_stack_lvl+0x33/0x46 > > [ 5554.777792] ? kernel_sendpage+0x60/0x220 > > [ 5554.778672] print_report.cold.12+0x499/0x6b7 > > [ 5554.779628] ? tcp_release_cb+0x46/0x200 > > [ 5554.780577] ? kernel_sendpage+0x60/0x220 > > [ 5554.781516] kasan_report+0xa3/0x120 > > [ 5554.782361] ? inet_sendmsg+0xa0/0xa0 > > [ 5554.783217] ? kernel_sendpage+0x60/0x220 > > [ 5554.784191] kernel_sendpage+0x60/0x220 > > [ 5554.785247] svc_tcp_sendmsg+0x206/0x2e0 [sunrpc] > > [ 5554.787188] ? svc_tcp_send_kvec.isra.20.constprop.29+0xa0/0xa0 [sunrpc] > > [ 5554.789364] ? refcount_dec_not_one+0xa0/0x120 > > [ 5554.790402] ? refcount_warn_saturate+0x120/0x120 > > [ 5554.791495] ? __rcu_read_unlock+0x4e/0x250 > > [ 5554.792575] ? __mutex_lock_slowpath+0x10/0x10 > > [ 5554.793571] ? tcp_release_cb+0x46/0x200 > > [ 5554.794443] svc_tcp_sendto+0x14f/0x2e0 [sunrpc] > > [ 5554.796182] ? svc_addsock+0x370/0x370 [sunrpc] > > [ 5554.797924] ? svc_sock_secure_port+0x27/0x50 [sunrpc] > > [ 5554.799848] ? svc_recv+0xab0/0xfa0 [sunrpc] > > [ 5554.801434] svc_send+0x9c/0x260 [sunrpc] > > [ 5554.802963] nfsd+0x170/0x270 [nfsd] > > [ 5554.804140] ? nfsd_shutdown_threads+0xe0/0xe0 [nfsd] > > [ 5554.805631] kthread+0x160/0x190 > > [ 5554.806354] ? kthread_complete_and_exit+0x20/0x20 > > [ 5554.807401] ret_from_fork+0x1f/0x30 > > [ 5554.808206] </TASK> > > [ 5554.808699] ================================================================== > > [ 5554.810486] Disabling lock debugging due to kernel taint > > [ 5554.811772] BUG: kernel NULL pointer dereference, address: 0000000000000008 > > [ 5554.813236] #PF: supervisor read access in kernel mode > > [ 5554.814345] #PF: error_code(0x0000) - not-present page > > [ 5554.815462] PGD 0 P4D 0 > > [ 5554.816032] Oops: 0000 [#1] PREEMPT SMP KASAN PTI > > [ 5554.817057] CPU: 1 PID: 2590 Comm: nfsd Tainted: G B > > 6.0.0-rc1+ #84 > > [ 5554.818677] Hardware name: VMware, Inc. VMware Virtual > > Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 > > [ 5554.821028] RIP: 0010:kernel_sendpage+0x60/0x220 > > [ 5554.822138] Code: 24 a0 00 00 00 e8 a0 98 83 ff 49 83 bc 24 a0 00 > > 00 00 00 0f 84 9f 00 00 00 48 8d 43 08 48 89 c7 48 89 44 24 08 e8 80 > > 98 83 ff <4c> 8b 63 08 41 f6 c4 01 0f 85 ee 00 00 00 0f 1f 44 00 00 48 > > 89 df > > [ 5554.826047] RSP: 0018:ffff888017ef7c38 EFLAGS: 00010296 > > [ 5554.827192] RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffffa3b173b6 > > [ 5554.828715] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffa6b16260 > > [ 5554.830237] RBP: ffff8880057ac380 R08: fffffbfff4d62c4d R09: fffffbfff4d62c4d > > [ 5554.831757] R10: ffffffffa6b16267 R11: fffffbfff4d62c4c R12: ffffffffa545e6a0 > > [ 5554.833341] R13: ffff8880057ac3a0 R14: 0000000000001000 R15: 0000000000000000 > > [ 5554.834881] FS: 0000000000000000(0000) GS:ffff888057c80000(0000) > > knlGS:0000000000000000 > > [ 5554.836590] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 5554.837819] CR2: 0000000000000008 CR3: 000000000677e004 CR4: 00000000001706e0 > > [ 5554.839374] Call Trace: > > [ 5554.839919] <TASK> > > [ 5554.840400] svc_tcp_sendmsg+0x206/0x2e0 [sunrpc] > > [ 5554.842066] ? svc_tcp_send_kvec.isra.20.constprop.29+0xa0/0xa0 [sunrpc] > > [ 5554.844194] ? refcount_dec_not_one+0xa0/0x120 > > [ 5554.845239] ? refcount_warn_saturate+0x120/0x120 > > [ 5554.846275] ? __rcu_read_unlock+0x4e/0x250 > > [ 5554.847199] ? __mutex_lock_slowpath+0x10/0x10 > > [ 5554.848171] ? tcp_release_cb+0x46/0x200 > > [ 5554.849039] svc_tcp_sendto+0x14f/0x2e0 [sunrpc] > > [ 5554.850667] ? svc_addsock+0x370/0x370 [sunrpc] > > [ 5554.852285] ? svc_sock_secure_port+0x27/0x50 [sunrpc] > > [ 5554.854420] ? svc_recv+0xab0/0xfa0 [sunrpc] > > [ 5554.856187] svc_send+0x9c/0x260 [sunrpc] > > [ 5554.857773] nfsd+0x170/0x270 [nfsd] > > [ 5554.859009] ? nfsd_shutdown_threads+0xe0/0xe0 [nfsd] > > [ 5554.860602] kthread+0x160/0x190 > > [ 5554.861400] ? kthread_complete_and_exit+0x20/0x20 > > [ 5554.862452] ret_from_fork+0x1f/0x30 > > [ 5554.863265] </TASK> > > [ 5554.863756] Modules linked in: rdma_ucm ib_uverbs rpcrdma rdma_cm > > iw_cm ib_cm ib_core nfsd nfs_acl lockd grace ext4 mbcache jbd2 fuse > > xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT > > nf_reject_ipv4 nft_compat nf_tables nfnetlink tun bridge stp llc bnep > > vmw_vsock_vmci_transport vsock intel_rapl_msr intel_rapl_common > > snd_seq_midi snd_seq_midi_event crct10dif_pclmul crc32_pclmul > > vmw_balloon ghash_clmulni_intel joydev pcspkr snd_ens1371 > > snd_ac97_codec ac97_bus snd_seq btusb btrtl btbcm btintel snd_pcm > > snd_timer snd_rawmidi snd_seq_device bluetooth rfkill snd ecdh_generic > > ecc soundcore vmw_vmci i2c_piix4 auth_rpcgss sunrpc ip_tables xfs > > libcrc32c sr_mod cdrom sg crc32c_intel nvme serio_raw nvme_core t10_pi > > crc64_rocksoft crc64 vmwgfx drm_ttm_helper ttm ahci drm_kms_helper > > ata_generic syscopyarea sysfillrect sysimgblt fb_sys_fops vmxnet3 > > libahci ata_piix drm libata > > [ 5554.880681] CR2: 0000000000000008 > > [ 5554.881539] ---[ end trace 0000000000000000 ]--- > > -- > Jeff Layton <jlayton@xxxxxxxxxx>
