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Alan Stern authored
The isd200 sub-driver in usb-storage uses the HEADS and SECTORS values in the ATA ID information to calculate cylinder and head values when creating a CDB for READ or WRITE commands. The calculation involves division and modulus operations, which will cause a crash if either of these values is 0. While this never happens with a genuine device, it could happen with a flawed or subversive emulation, as reported by the syzbot fuzzer. Protect against this possibility by refusing to bind to the device if either the ATA_ID_HEADS or ATA_ID_SECTORS value in the device's ID information is 0. This requires isd200_Initialization() to return a negative error code when initialization fails; currently it always returns 0 (even when there is an error). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: syzbot+28748250ab47a8f04100@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-usb/0000000000003eb868061245ba7f@google.com/ Fixes: 1da177e4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/b1e605ea-333f-4ac0-9511-da04f411763e@rowland.harvard.eduSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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