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author | Alexander Egorenkov <egorenar@linux.ibm.com> | 2021-09-09 13:20:56 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 13:27:56 +0300 |
commit | 0346f8a2c5ecef2fea9932ebeb447c0d957f749a (patch) | |
tree | d95794f711e2a063f0049d3df01f821c002af5f9 /drivers/s390 | |
parent | cc9d96c9f9e009b8a33385fab9b78ccf92e51d6e (diff) | |
download | linux-0346f8a2c5ecef2fea9932ebeb447c0d957f749a.tar.xz |
s390/sclp: fix Secure-IPL facility detection
commit d76b14f3971a0638b6cd0da289f8b48acee287d0 upstream.
Prevent out-of-range access if the returned SCLP SCCB response is smaller
in size than the address of the Secure-IPL flag.
Fixes: c9896acc7851 ("s390/ipl: Provide has_secure sysfs attribute")
Cc: stable@vger.kernel.org # 5.2+
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390')
-rw-r--r-- | drivers/s390/char/sclp_early.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c index cc5e84b80c69..faa3a4b8ed91 100644 --- a/drivers/s390/char/sclp_early.c +++ b/drivers/s390/char/sclp_early.c @@ -40,13 +40,14 @@ static void __init sclp_early_facilities_detect(struct read_info_sccb *sccb) sclp.has_gisaf = !!(sccb->fac118 & 0x08); sclp.has_hvs = !!(sccb->fac119 & 0x80); sclp.has_kss = !!(sccb->fac98 & 0x01); - sclp.has_sipl = !!(sccb->cbl & 0x4000); if (sccb->fac85 & 0x02) S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP; if (sccb->fac91 & 0x40) S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_GUEST; if (sccb->cpuoff > 134) sclp.has_diag318 = !!(sccb->byte_134 & 0x80); + if (sccb->cpuoff > 137) + sclp.has_sipl = !!(sccb->cbl & 0x4000); sclp.rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2; sclp.rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2; sclp.rzm <<= 20; |