[Bug 786208] Re: Missing checks for non-existent device in ide_exec_cmd
[Expired for QEMU because there has been no activity for 60 days.] ** Changed in: qemu Status: Incomplete => Expired -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/786208 Title: Missing checks for non-existent device in ide_exec_cmd Status in QEMU: Expired Bug description: Several calls in the ide_exec_cmd handler are missing checks for (!s->bs) or similar, resulting in NULL pointer dereferences, divide- by-zero, or possibly other badness if the guest performs operations on a non-existent IDE master. For example, the WIN_READ_NATIVE_MAX command does a 'ide_set_sector(s, s->nb_sectors - 1);', which does 'cyl = sector_num / (s->heads * s->sectors);', which will fail with a divide-by-zero if heads = sectors = 0. And WIN_MULTREAD also does not check for s->bs, but does a 'ide_sector_read(s);', which will do 'bdrv_read(s->bs, sector_num, s->io_buffer, n);' on a NULL s->bs, leading to a segfault. I do not *believe* that a malicious guest can do anything more than cause a crash with these bugs. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/786208/+subscriptions
[Bug 786208] Re: Missing checks for non-existent device in ide_exec_cmd
The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting older bugs to "Incomplete" now. If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Or mark it as "Fix Released" if the problem has been solved with a newer version of QEMU already. Thank you and sorry for the inconvenience. ** Changed in: qemu Assignee: John Snow (jnsnow) => (unassigned) ** Changed in: qemu Status: New => Incomplete -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/786208 Title: Missing checks for non-existent device in ide_exec_cmd Status in QEMU: Incomplete Bug description: Several calls in the ide_exec_cmd handler are missing checks for (!s->bs) or similar, resulting in NULL pointer dereferences, divide- by-zero, or possibly other badness if the guest performs operations on a non-existent IDE master. For example, the WIN_READ_NATIVE_MAX command does a 'ide_set_sector(s, s->nb_sectors - 1);', which does 'cyl = sector_num / (s->heads * s->sectors);', which will fail with a divide-by-zero if heads = sectors = 0. And WIN_MULTREAD also does not check for s->bs, but does a 'ide_sector_read(s);', which will do 'bdrv_read(s->bs, sector_num, s->io_buffer, n);' on a NULL s->bs, leading to a segfault. I do not *believe* that a malicious guest can do anything more than cause a crash with these bugs. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/786208/+subscriptions
[Qemu-devel] [Bug 786208] Re: Missing checks for non-existent device in ide_exec_cmd
** Changed in: qemu Assignee: (unassigned) => John Snow (jnsnow) -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/786208 Title: Missing checks for non-existent device in ide_exec_cmd Status in QEMU: New Bug description: Several calls in the ide_exec_cmd handler are missing checks for (!s->bs) or similar, resulting in NULL pointer dereferences, divide- by-zero, or possibly other badness if the guest performs operations on a non-existent IDE master. For example, the WIN_READ_NATIVE_MAX command does a 'ide_set_sector(s, s->nb_sectors - 1);', which does 'cyl = sector_num / (s->heads * s->sectors);', which will fail with a divide-by-zero if heads = sectors = 0. And WIN_MULTREAD also does not check for s->bs, but does a 'ide_sector_read(s);', which will do 'bdrv_read(s->bs, sector_num, s->io_buffer, n);' on a NULL s->bs, leading to a segfault. I do not *believe* that a malicious guest can do anything more than cause a crash with these bugs. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/786208/+subscriptions
