[merged] sysctl-check-for-uint_max-before-unsigned-int-min-max.patch removed from -mm tree

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The patch titled
     Subject: sysctl: check for UINT_MAX before unsigned int min/max
has been removed from the -mm tree.  Its filename was
     sysctl-check-for-uint_max-before-unsigned-int-min-max.patch

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

------------------------------------------------------
From: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Subject: sysctl: check for UINT_MAX before unsigned int min/max

Mikulas noticed in the existing do_proc_douintvec_minmax_conv() and
do_proc_dopipe_max_size_conv() introduced in this patchset, that they
inconsistently handle overflow and min/max range inputs:

For example:

  0 ... param->min - 1 ---> ERANGE
  param->min ... param->max ---> the value is accepted
  param->max + 1 ... 0x100000000L + param->min - 1 ---> ERANGE
  0x100000000L + param->min ... 0x100000000L + param->max ---> EINVAL
  0x100000000L + param->max + 1, 0x200000000L + param->min - 1 ---> ERANGE
  0x200000000L + param->min ... 0x200000000L + param->max ---> EINVAL
  0x200000000L + param->max + 1, 0x300000000L + param->min - 1 ---> ERANGE

In do_proc_do*() routines which store values into unsigned int variables
(4 bytes wide for 64-bit builds), first validate that the input unsigned
long value (8 bytes wide for 64-bit builds) will fit inside the smaller
unsigned int variable.  Then check that the unsigned int value falls
inside the specified parameter min, max range.  Otherwise the unsigned
long -> unsigned int conversion drops leading bits from the input value,
leading to the inconsistent pattern Mikulas documented above.

Link: http://lkml.kernel.org/r/1507658689-11669-5-git-send-email-joe.lawrence@xxxxxxxxxx
Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Reviewed-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 kernel/sysctl.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff -puN kernel/sysctl.c~sysctl-check-for-uint_max-before-unsigned-int-min-max kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-check-for-uint_max-before-unsigned-int-min-max
+++ a/kernel/sysctl.c
@@ -2576,12 +2576,13 @@ static int do_proc_douintvec_minmax_conv
 	if (write) {
 		unsigned int val = *lvalp;
 
+		if (*lvalp > UINT_MAX)
+			return -EINVAL;
+
 		if ((param->min && *param->min > val) ||
 		    (param->max && *param->max < val))
 			return -ERANGE;
 
-		if (*lvalp > UINT_MAX)
-			return -EINVAL;
 		*valp = val;
 	} else {
 		unsigned int val = *valp;
@@ -2632,17 +2633,18 @@ static int do_proc_dopipe_max_size_conv(
 	struct do_proc_dopipe_max_size_conv_param *param = data;
 
 	if (write) {
-		unsigned int val = round_pipe_size(*lvalp);
+		unsigned int val;
 
+		if (*lvalp > UINT_MAX)
+			return -EINVAL;
+
+		val = round_pipe_size(*lvalp);
 		if (val == 0)
 			return -EINVAL;
 
 		if (param->min && *param->min > val)
 			return -ERANGE;
 
-		if (*lvalp > UINT_MAX)
-			return -EINVAL;
-
 		*valp = val;
 	} else {
 		unsigned int val = *valp;
_

Patches currently in -mm which might be from joe.lawrence@xxxxxxxxxx are


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