From: Colin Ian King <colin.k...@canonical.com> Shifting unsigned char b by an int type can lead to sign-extension overflow. For example, if b is 0xff and the shift is 24, then top bit is sign-extended so the final value passed to writeq has all the upper 32 bits set. Fix this by casting b to a 64 bit unsigned before the shift.
Detected by CoverityScan, CID#1465246 ("Unintended sign extension") Signed-off-by: Colin Ian King <colin.k...@canonical.com> --- drivers/char/ipmi/ipmi_si_mem_io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_mem_io.c b/drivers/char/ipmi/ipmi_si_mem_io.c index 1b869d530884..fd0ec8d6bf0e 100644 --- a/drivers/char/ipmi/ipmi_si_mem_io.c +++ b/drivers/char/ipmi/ipmi_si_mem_io.c @@ -51,7 +51,7 @@ static unsigned char mem_inq(const struct si_sm_io *io, unsigned int offset) static void mem_outq(const struct si_sm_io *io, unsigned int offset, unsigned char b) { - writeq(b << io->regshift, (io->addr)+(offset * io->regspacing)); + writeq((u64)b << io->regshift, (io->addr)+(offset * io->regspacing)); } #endif -- 2.17.0 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer