I have been struggling to update my machines to fedora 7 with the latest kernel. We are getting a crash of the kernel as shown below.

This happens when we run a "yum upgrade" operation. Our repositories are available on the local LAN segment and mounted via Autofs 5 over NFS4. The system is generally stable using this configuration for other purposes although we occasionally see the same failure when other operations are running. I have been unable to find any reference to this failure in association with this version of the kernel, although similar failures were reported about six months ago for 2.6.17 pre-release kernels.

Does anybody have any idea what is causing the failure, whether this is something that there is a fix for, and whether other people are seeing it and if so what work rounds they have used.

Traceback on the console is as follows:

BUG: unable to handle kernel NULL pointer dereference at virtual address 0000000                      c
printing eip:
f8cea941
*pde = 24fd0067
*pte = 00000000
Oops: 0000 [#1]
SMP
last sysfs file: /kernel/uevent_seqnum
Modules linked in: appletalk nfs nfsd exportfs lockd nfs_acl autofs4 rpcsec_gss_                      krb5 auth_rpcgss des sunrpc bonding ipv6 ext2 loop video sbs button dock battery                       ac sr_mod cdrom ata_generic e100 mii parport_pc parport ata_piix i2c_piix4 seri                      o_raw rtc_cmos libata i2c_core e1000 floppy sg dm_snapshot dm_zero dm_mirror dm_                      mod sym53c8xx scsi_transport_spi sd_mod scsi_mod raid456 xor raid1 ext3 jbd mbca                      che ehci_hcd ohci_hcd uhci_hcd
CPU:    2
EIP:    0060:[<f8cea941>]    Not tainted VLI
EFLAGS: 00210246   (2.6.22.1-41.fc7 #1)
EIP is at nfs_update_inode+0xba/0x649 [nfs]
eax: 00000000   ebx: 000081a4   ecx: 000081a4   edx: 00008000
esi: e999eb40   edi: f40ccab0   ebp: edd108c8   esp: deb91de4
ds: 007b   es: 007b   fs: 00d8 gs: 0033 ss: 0068
Process umount.nfs4 (pid: 22737, ti=deb91000 task=f5058c00 task.ti=deb91000)
Stack: c300034c eddc9740 00000004 00000000 f5058c00 c0436fe2 deb91dfc 00000000
       f40ccab0 edd10798 00cd4f8f c042f18c eddc96c0 00000000 edd108c8 f40ccab0
       eddc96c0 edd108c8 f8cebf0d f40cca00 00000000 f8cf8465 f40cca00 df2fd010
Call Trace:
[<c0436fe2>] wake_bit_function+0x0/0x3c
[<c042f18c>] sigprocmask+0xa1/0xbe
[<f8cebf0d>] nfs_post_op_update_inode+0x27/0x33 [nfs]
[<f8cf8465>] nfs4_proc_delegreturn+0x131/0x172 [nfs]
[<f8d02b85>] nfs_do_return_delegation+0xf/0x1d [nfs]
[<f8ce9364>] nfs_dentry_iput+0x1d/0x60 [nfs]
[<c0487922>] shrink_dcache_for_umount_subtree+0x194/0x1de
[<c04742f2>] add_partial+0x19/0x20
[<c0474fbb>] __slab_free+0x5c/0x235
[<c04774e8>] percpu_depopulate+0x10/0x1a
[<c048834a>] shrink_dcache_for_umount+0x2a/0x36
[<c047a8ee>] generic_shutdown_super+0x15/0xb7
[<c047a9b4>] kill_anon_super+0x9/0x2f
[<f8ceca03>] nfs_kill_super+0xc/0x14 [nfs]
[<c047aa43>] deactivate_super+0x52/0x65
[<c048b983>] expire_mount_list+0xf0/0x125
[<c048c8c3>] shrink_submounts+0x32/0xab
[<c048baab>] sys_umount+0xf3/0x21a
[<c04527db>] audit_syscall_entry+0x10d/0x137
[<c048bbe9>] sys_oldumount+0x17/0x1a
[<c0404f8e>] syscall_call+0x7/0xb
=======================
Code: 20 0f b7 5d 6e 89 c8 89 da 25 00 f0 00 00 81 e2 00 f0 00 00 39 c2 0f 85 92                       04 00 00 8b 85 9c 00 00 00 8b b0 64 01 00 00 8b 40 38 <3b> 68 0c 75 52 83 c7 44                       89 7c 24 30 8b 7c 24 20 8d 46 78 89 44
EIP: [<f8cea941>] nfs_update_inode+0xba/0x649 [nfs] SS:ESP 0068:deb91de4

Regards, Howard

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Howard Wilkinson	Phone:	+44(20)76907075
Coherent Technology Limited	Fax:
23 Northampton Square,	Mobile:	+44(7980)639379
United Kingdom, EC1V 0HL	Email:	howard@cohtech.com