devicemodel: hw: pci: gvt: Fix out of bounds error #8118
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hw/pci/gvt.c:263:41: error: array subscript 257 is above array bounds of ‘uint8_t[256]’ {aka ‘unsigned char[256]’} [-Werror=array-bounds]
263 | gvt->host_config[cap_ptr + 4]);
| ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
hw/pci/gvt.c:48:17: note: while referencing ‘host_config’
48 | uint8_t host_config[PCI_REGMAX+1];
| ^~~~~~~~~~~
With the additional condition cap_ptr < PCI_REGMAX - 16 it is ensured
that we never read config data from places we shouldn't read from.
12 (offset) + 4 (pci_set_cfgdata32) = 16
I would consider this a workaround that gets the job done for
now. However with this approach we can miss the last capabilities in
some edge cases.
Tracked-On: projectacrn#8116
Signed-off-by: Marius Rodi <[email protected]>
ghost
requested a review
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Can one of the admins verify this patch? |
|
As stated, this fix is more of a workaround. I don't have the time to do this the right way currently. Maybe someone else can have a deeper look into this? |
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start to run premerge test |
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@ywan170 could you please review this PR? |
ywan170
reviewed
Sep 22, 2022
| 12 (offset) + 4 (pci_set_cfgdata32) = 16 | ||
| */ | ||
| while (cap_ptr != 0 && cap_ptr < PCI_REGMAX - 16) { |
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Should we change the pci_set_cfgdata32 to pci_set_cfgdata8. And if the cap_ptr != 0 but exceeds the "PCI_REGMAX - 16" then print some warning logs as some capabilities are lost.
@yakuizhao to comment
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close this PR as the owner has been ghost account. |
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With the additional condition
cap_ptr < PCI_REGMAX - 16it is ensured that we never read config data from places we shouldn't read from.12 (offset) + 4 (pci_set_cfgdata32) = 16
I would consider this a workaround that gets the job done for now. However with this approach we can miss the last capabilities in some edge cases.
Tracked-On: #8116
Signed-off-by: Marius Rodi [email protected]