Bug 25960

Summary: mounting unclosed CD-R causes kernel panic
Product: Base System Reporter: Alexey V. Neyman <avn>
Component: kernAssignee: Søren Schmidt <sos>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: 4.2-STABLE   
Hardware: Any   
OS: Any   

Description Alexey V. Neyman 2001-03-21 07:40:01 UTC 
making unclosed CD-R (burncd without fixate command) and later mounting it
causes kernel panic:
Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0xc0c21000
fault code              = supervisor write, page not present
instruction pointer     = 0x8:0xc01f2d82
stack pointer           = 0x10:0xc025b8d0
frame pointer           = 0x10:0xc025b8e0
code segment            = base rx0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = Idle
interrupt mask          = bio

backtrace of the stack in gdb shows:
#0  0xc013ed5e in dumpsys ()
#1  0xc013eb7f in boot ()
#2  0xc013ef15 in panic ()
#3  0xc011d759 in db_panic ()
#4  0xc011d6f9 in db_command ()
#5  0xc011d7be in db_command_loop ()
#6  0xc011f8cb in db_trap ()
#7  0xc020a402 in kdb_trap ()
#8  0xc0219820 in trap_fatal ()
#9  0xc02194f9 in trap_pfault ()
#10 0xc021909b in trap ()
#11 0xc01f2d82 in atapi_read ()
#12 0xc01f2823 in atapi_interrupt ()
#13 0xc01ec33e in ata_intr ()

also (it may be related) burncd fixate produces an error
like 'ioctl(...): Input/output error.

How-To-Repeat: 
#burncd -f /dev/acd0c data i1.iso
#mount_cd9660 /dev/acd0c /cdrom
Comment 1 Poul-Henning Kamp freebsd_committer freebsd_triage 2001-03-28 19:24:29 UTC 
Responsible Changed
From-To: gnats-admin->sos

MrATA issue.
Comment 2 Søren Schmidt freebsd_committer freebsd_triage 2001-04-02 20:16:08 UTC 
State Changed
From-To: open->closed

You cannot mount or use an unfixated CDR/CDRW, granted the  
fs code should be more robust, but thats another matter.