Missing checks for non-existent device in ide_exec_cmd
Bug #786208 reported by
Nelson Elhage
This bug affects 1 person
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| QEMU |
Expired
|
Undecided
|
Unassigned | ||
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_
I do not *believe* that a malicious guest can do anything more than cause a crash with these bugs.
| Changed in qemu: | |
| assignee: | nobody → John Snow (jnsnow) |
Revision history for this message
| Thomas Huth (th-huth) wrote | #1 |
| Changed in qemu: | |
| assignee: | John Snow (jnsnow) → nobody |
| status: | New → Incomplete |
Revision history for this message
| Launchpad Janitor (janitor) wrote | #2 |
| Changed in qemu: | |
| status: | Incomplete → Expired |
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