[Note: please cc me on answers since I'm not subscribed to the kernel list] Trying to mount a DVD drive connected to an Adaptec 29160 SCSI controller (through an IDE-to-SCSI bridge), I get a crash in the kernel. The mount command: $: mount /dev/sr1 /dvd The log: BUG: unable to handle kernel NULL pointer dereference at virtual address 0000000c printing eip: c0274f77 *pde = 00000000 Oops: 0000 [#1] PREEMPT last sysfs file: /class/net/eth2/ifindex Modules linked in: pl2303 usbserial softdog snd_pcm_oss snd_mixer_oss snd_cs46xx gameport snd_rawmidi snd_seq_device snd_ac97_codec snd_ac97_bus snd_pcm snd_timer snd soundcore snd_page_alloc zoran i2c_algo_bit videodev saa7 111 i2c_core pegasus arc4 ppp_mppe ppp_deflate ppp_generic slhc usblp CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00010096 (2.6.16-rc3-mm1 #2) EIP is at elv_may_queue+0xc/0x2b eax: 00000000 ebx: d8712000 ecx: 00000000 edx: 00000000 esi: 00000000 edi: 00000000 ebp: 00000010 esp: d8713ccc ds: 007b es: 007b ss: 0068 Process mount (pid: 3328, threadinfo=d8712000 task=e2bfa560) Stack: <0>d8712000 00000000 c027762b e2bfa560 c0111f3e 00000000 00000000 00000000 00000082 d8712000 00000000 c17f1400 00000000 c02778d9 00000010 00000000 e978c82a 00000000 d8713d98 00000000 e978c82a 00000000 c0277e11 00000001 Call Trace: get_request+0x27/0x2b8 default_wake_function+0x0/0xc get_request_wait+0x1d/0x12b blk_execute_rq+0x96/0xcf blk_end_sync_rq+0x0/0x1d get_request_wait+0x1d/0x12b mempool_free+0x48/0x9b blk_get_request+0x28/0x65 scsi_execute+0x2c/0xde mempool_free+0x48/0x9b sr_do_ioctl+0x82/0x22a kzalloc+0x1b/0x50 sr_read_tochdr+0x6a/0x89 cdrom_count_tracks+0x66/0x171 open_for_data+0xb6/0x331 kobject_get+0xf/0x13 get_disk+0x62/0xbd cdrom_open+0x41/0xf4 kobject_get+0xf/0x13 sr_block_open+0x69/0x9d do_open+0xd8/0x2f2 bdget+0xed/0xfc bdev_set+0x0/0x8 blkdev_open+0x25/0x5c blkdev_open+0x0/0x5c __dentry_open+0xd8/0x20a nameidata_to_filp+0x28/0x3b do_filp_open+0x4b/0x4d do_page_fault+0x162/0x5b2 do_sys_open+0x42/0xbb syscall_call+0x7/0xb Code: 24 89 f0 ff 53 2c eb e6 53 89 c3 8b 40 0c 8b 00 8b 48 30 85 c9 75 02 5b c3 89 d8 ff d1 eb f8 83 ec 08 89 7 4 24 04 89 1c 24 89 c6 <8b> 40 0c 8b 00 8b 58 34 31 c0 85 db 75 0b 8b 1c 24 8b 74 24 04 <6>note: mount[3328] exited with preempt_count 1