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From 794229b5711a96a488d85dd719511a278b4a4956 Mon Sep 17 00:00:00 2001
From: Ryan Sullivan <rysulliv@redhat.com>
Date: Fri, 27 Jan 2023 11:25:43 -0500
Subject: [KPATCH CVE-2022-4378] kpatch fixes for CVE-2022-4378


Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-7/-/merge_requests/51
Approved-by: Yannick Cote (@ycote1)
Approved-by: Joe Lawrence (@joe.lawrence)
Kernels:
3.10.0-1160.76.1.el7
3.10.0-1160.80.1.el7
3.10.0-1160.81.1.el7
3.10.0-1160.83.1.el7

Changes since last build:
[x86_64]:
sysctl.o: changed function: __do_proc_dointvec
sysctl.o: changed function: __do_proc_douintvec
sysctl.o: changed function: __do_proc_doulongvec_minmax
sysctl.o: changed function: proc_dostring
sysctl.o: changed function: proc_get_long.constprop.13

[ppc64le]:
sysctl.o: changed function: __do_proc_doulongvec_minmax
sysctl.o: changed function: proc_do_cad_pid
sysctl.o: changed function: proc_dointvec
sysctl.o: changed function: proc_dointvec_jiffies
sysctl.o: changed function: proc_dointvec_minmax
sysctl.o: changed function: proc_dointvec_minmax_coredump
sysctl.o: changed function: proc_dointvec_minmax_sysadmin
sysctl.o: changed function: proc_dointvec_ms_jiffies
sysctl.o: changed function: proc_dointvec_userhz_jiffies
sysctl.o: changed function: proc_dopipe_max_size
sysctl.o: changed function: proc_dostring
sysctl.o: changed function: proc_dostring_coredump
sysctl.o: changed function: proc_douintvec
sysctl.o: changed function: proc_douintvec_minmax
sysctl.o: changed function: proc_doulongvec_minmax
sysctl.o: changed function: proc_doulongvec_ms_jiffies_minmax
sysctl.o: changed function: proc_get_long.constprop.13
sysctl.o: changed function: sysrq_sysctl_handler
sysctl.o: new function: __do_proc_dointvec

---------------------------

Modifications:
added '__attribute__((optimize("-fno-optimize-sibling-calls")))' to
proc_dointvec_jiffies(), proc_dointvec_ms_jiffies(), proc_doulongvec_ms_jiffies_minmax(),
proc_doulongvec_minmax(), proc_dointvec_userhz_jiffies(), and proc_dointvec() definitions.

commit f4f6d6bf0cd6fc3d1b88341f784b2f7e8589ff61
Author: Wander Lairson Costa <wander@redhat.com>
Date:   Tue Dec 13 08:13:31 2022 -0300

    proc: avoid integer type confusion in get_proc_long

    Bugzilla: https://bugzilla.redhat.com/2152565
    CVE: CVE-2022-4378

    commit e6cfaf34be9fcd1a8285a294e18986bfc41a409c
    Author: Linus Torvalds <torvalds@linux-foundation.org>
    Date:   Mon Dec 5 11:33:40 2022 -0800

        proc: avoid integer type confusion in get_proc_long

        proc_get_long() is passed a size_t, but then assigns it to an 'int'
        variable for the length.  Let's not do that, even if our IO paths are
        limited to MAX_RW_COUNT (exactly because of these kinds of type errors).

        So do the proper test in the rigth type.

        Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
        Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

    Signed-off-by: Wander Lairson Costa <wander@redhat.com>

commit c727ac3f665ed51c096edeedf039552cea6053f6
Author: Wander Lairson Costa <wander@redhat.com>
Date:   Tue Dec 13 08:12:23 2022 -0300

    proc: proc_skip_spaces() shouldn't think it is working on C strings

    Bugzilla: https://bugzilla.redhat.com/2152565
    CVE: CVE-2022-4378

    Conflicts: some context hunks because we are way behind upstream.

    commit bce9332220bd677d83b19d21502776ad555a0e73
    Author: Linus Torvalds <torvalds@linux-foundation.org>
    Date:   Mon Dec 5 12:09:06 2022 -0800

        proc: proc_skip_spaces() shouldn't think it is working on C strings

        proc_skip_spaces() seems to think it is working on C strings, and ends
        up being just a wrapper around skip_spaces() with a really odd calling
        convention.

        Instead of basing it on skip_spaces(), it should have looked more like
        proc_skip_char(), which really is the exact same function (except it
        skips a particular character, rather than whitespace).  So use that as
        inspiration, odd coding and all.

        Now the calling convention actually makes sense and works for the
        intended purpose.

        Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
        Acked-by: Eric Dumazet <edumazet@google.com>
        Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

    Signed-off-by: Wander Lairson Costa <wander@redhat.com>

Signed-off-by: Ryan Sullivan <rysulliv@redhat.com>
---
 kernel/sysctl.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 62e2788cf09a..6f7d80afda89 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1999,13 +1999,14 @@ int proc_dostring(struct ctl_table *table, int write,
 			       (char __user *)buffer, lenp, ppos);
 }
 
-static size_t proc_skip_spaces(char **buf)
+static void proc_skip_spaces(char **buf, size_t *size)
 {
-	size_t ret;
-	char *tmp = skip_spaces(*buf);
-	ret = tmp - *buf;
-	*buf = tmp;
-	return ret;
+	while (*size) {
+		if (!isspace(**buf))
+			break;
+		(*size)--;
+		(*buf)++;
+	}
 }
 
 static void proc_skip_char(char **buf, size_t *size, const char v)
@@ -2074,13 +2075,12 @@ static int proc_get_long(char **buf, size_t *size,
 			  unsigned long *val, bool *neg,
 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
 {
-	int len;
 	char *p, tmp[TMPBUFLEN];
+	ssize_t len = *size;
 
-	if (!*size)
+	if (len <= 0)
 		return -EINVAL;
 
-	len = *size;
 	if (len > TMPBUFLEN - 1)
 		len = TMPBUFLEN - 1;
 
@@ -2250,7 +2250,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		bool neg;
 
 		if (write) {
-			left -= proc_skip_spaces(&kbuf);
+			proc_skip_spaces(&kbuf, &left);
 
 			if (!left)
 				break;
@@ -2281,7 +2281,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err && left)
-		left -= proc_skip_spaces(&kbuf);
+		proc_skip_spaces(&kbuf, &left);
 free:
 	if (write) {
 		free_page(page);
@@ -2331,7 +2331,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
 	if (IS_ERR(kbuf))
 		return -EINVAL;
 
-	left -= proc_skip_spaces(&p);
+	proc_skip_spaces(&p, &left);
 	if (!left) {
 		err = -EINVAL;
 		goto out_free;
@@ -2351,7 +2351,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
 	}
 
 	if (!err && left)
-		left -= proc_skip_spaces(&p);
+		proc_skip_spaces(&p, &left);
 
 out_free:
 	kfree(kbuf);
@@ -2457,6 +2457,7 @@ static int do_proc_douintvec(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_dointvec(struct ctl_table *table, int write,
 		     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2775,7 +2776,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 		if (write) {
 			bool neg;
 
-			left -= proc_skip_spaces(&kbuf);
+			proc_skip_spaces(&kbuf, &left);
 
 			err = proc_get_long(&kbuf, &left, &val, &neg,
 					     proc_wspace_sep,
@@ -2800,7 +2801,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err)
-		left -= proc_skip_spaces(&kbuf);
+		proc_skip_spaces(&kbuf, &left);
 free:
 	if (write) {
 		free_page(page);
@@ -2839,6 +2840,7 @@ static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_doulongvec_minmax(struct ctl_table *table, int write,
 			   void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2862,6 +2864,7 @@ int proc_doulongvec_minmax(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
 				      void __user *buffer,
 				      size_t *lenp, loff_t *ppos)
@@ -2957,6 +2960,7 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_dointvec_jiffies(struct ctl_table *table, int write,
 			  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -2979,6 +2983,7 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
 				 void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -3002,6 +3007,7 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
+__attribute__((optimize("-fno-optimize-sibling-calls")))
 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
 			     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-- 
2.39.1