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authorColin Ian King <colin.king@canonical.com>2021-06-21 16:17:27 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2021-06-22 21:16:47 -0400
commit332a9dd1d86f1e7203fc7f0fd7e82f0b304200fe (patch)
tree26457d957e1545a7724470f37002c852714f1f34 /drivers/scsi/aic7xxx
parentf7c95d7460e342f812eaf9b4b74f100d5afaf258 (diff)
downloadlinux-332a9dd1d86f1e7203fc7f0fd7e82f0b304200fe.tar.bz2
scsi: aic7xxx: Fix unintentional sign extension issue on left shift of u8
The shifting of the u8 integer returned fom ahc_inb(ahc, port+3) by 24 bits to the left will be promoted to a 32 bit signed int and then sign-extended to a u64. In the event that the top bit of the u8 is set then all then all the upper 32 bits of the u64 end up as also being set because of the sign-extension. Fix this by casting the u8 values to a u64 before the 24 bit left shift. [ This dates back to 2002, I found the offending commit from the git history git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git, commit f58eb66c0b0a ("Update aic7xxx driver to 6.2.10...") ] Link: https://lore.kernel.org/r/20210621151727.20667-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Addresses-Coverity: ("Unintended sign extension")
Diffstat (limited to 'drivers/scsi/aic7xxx')
-rw-r--r--drivers/scsi/aic7xxx/aic7xxx_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/aic7xxx/aic7xxx_core.c b/drivers/scsi/aic7xxx/aic7xxx_core.c
index 4b04ab8908f8..a396f048a031 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_core.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_core.c
@@ -493,7 +493,7 @@ ahc_inq(struct ahc_softc *ahc, u_int port)
return ((ahc_inb(ahc, port))
| (ahc_inb(ahc, port+1) << 8)
| (ahc_inb(ahc, port+2) << 16)
- | (ahc_inb(ahc, port+3) << 24)
+ | (((uint64_t)ahc_inb(ahc, port+3)) << 24)
| (((uint64_t)ahc_inb(ahc, port+4)) << 32)
| (((uint64_t)ahc_inb(ahc, port+5)) << 40)
| (((uint64_t)ahc_inb(ahc, port+6)) << 48)