[merged] sysctl-fix-int-unsigned-long-assignments-in-int_min-case.patch removed from -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: sysctl: fix int -> unsigned long assignments in INT_MIN case
has been removed from the -mm tree.  Its filename was
     sysctl-fix-int-unsigned-long-assignments-in-int_min-case.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Ilya Dryomov <idryomov@xxxxxxxxx>
Subject: sysctl: fix int -> unsigned long assignments in INT_MIN case

The following

    if (val < 0)
        *lvalp = (unsigned long)-val;

is incorrect because the compiler is free to assume -val to be positive
and use a sign-extend instruction for extending the bit pattern.  This is
a problem if val == INT_MIN:

    # echo -2147483648 >/proc/sys/dev/scsi/logging_level
    # cat /proc/sys/dev/scsi/logging_level
    -18446744071562067968

Cast to unsigned long before negation - that way we first sign-extend and
then negate an unsigned, which is well defined.  With this:

    # cat /proc/sys/dev/scsi/logging_level
    -2147483648

Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Cc: Mikulas Patocka <mikulas@xxxxxxxxxxxxx>
Cc: Robert Xiao <nneonneo@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 kernel/sysctl.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff -puN kernel/sysctl.c~sysctl-fix-int-unsigned-long-assignments-in-int_min-case kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-fix-int-unsigned-long-assignments-in-int_min-case
+++ a/kernel/sysctl.c
@@ -1995,7 +1995,7 @@ static int do_proc_dointvec_conv(bool *n
 		int val = *valp;
 		if (val < 0) {
 			*negp = true;
-			*lvalp = (unsigned long)-val;
+			*lvalp = -(unsigned long)val;
 		} else {
 			*negp = false;
 			*lvalp = (unsigned long)val;
@@ -2201,7 +2201,7 @@ static int do_proc_dointvec_minmax_conv(
 		int val = *valp;
 		if (val < 0) {
 			*negp = true;
-			*lvalp = (unsigned long)-val;
+			*lvalp = -(unsigned long)val;
 		} else {
 			*negp = false;
 			*lvalp = (unsigned long)val;
@@ -2436,7 +2436,7 @@ static int do_proc_dointvec_jiffies_conv
 		unsigned long lval;
 		if (val < 0) {
 			*negp = true;
-			lval = (unsigned long)-val;
+			lval = -(unsigned long)val;
 		} else {
 			*negp = false;
 			lval = (unsigned long)val;
@@ -2459,7 +2459,7 @@ static int do_proc_dointvec_userhz_jiffi
 		unsigned long lval;
 		if (val < 0) {
 			*negp = true;
-			lval = (unsigned long)-val;
+			lval = -(unsigned long)val;
 		} else {
 			*negp = false;
 			lval = (unsigned long)val;
@@ -2484,7 +2484,7 @@ static int do_proc_dointvec_ms_jiffies_c
 		unsigned long lval;
 		if (val < 0) {
 			*negp = true;
-			lval = (unsigned long)-val;
+			lval = -(unsigned long)val;
 		} else {
 			*negp = false;
 			lval = (unsigned long)val;
_

Patches currently in -mm which might be from idryomov@xxxxxxxxx are


--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Newbies FAQ]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux