From daf9de90e88ffb2e303145733167327f92b869c2 Mon Sep 17 00:00:00 2001

From: Ryan Sullivan <rysulliv@redhat.com>

Date: Tue, 7 Feb 2023 12:08:05 -0500

Subject: [KPATCH CVE-2022-4378] kpatch fixes for CVE-2022-4378

Kernels:

4.18.0-425.3.1.el8

4.18.0-425.10.1.el8_7

Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-8/-/merge_requests/82

Approved-by: Joe Lawrence (@joe.lawrence)

Approved-by: Yannick Cote (@ycote1)

Changes since last build:

[x86_64]:

control.o: changed function: snd_ctl_elem_read

control.o: changed function: snd_ctl_ioctl

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_get_long.constprop.14

[ppc64le]:

control.o: changed function: snd_ctl_elem_read

control.o: changed function: snd_ctl_ioctl

sysctl.o: changed function: __do_proc_dointvec

sysctl.o: changed function: __do_proc_doulongvec_minmax

sysctl.o: changed function: proc_dopipe_max_size

sysctl.o: changed function: proc_douintvec

sysctl.o: changed function: proc_douintvec_minmax

sysctl.o: changed function: proc_get_long.constprop.14

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

Modifications: none

commit 8c873c04cfd546b8b29ae86dc35414cf4167d163

Author: Wander Lairson Costa <wander@redhat.com>

Date:   Mon Dec 12 15:43:15 2022 -0300

    proc: avoid integer type confusion in get_proc_long

    Bugzilla: https://bugzilla.redhat.com/2152571

    CVE: CVE-2022-4378

    Y-Commit: bbda4302821f46972d5139f9af87993a7a07306e

    O-Bugzilla: https://bugzilla.redhat.com/2152572

    O-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>

    Signed-off-by: Jarod Wilson <jarod@redhat.com>

commit 2347e6da850ca59e4730578b53d0e9339a1bb1e6

Author: Wander Lairson Costa <wander@redhat.com>

Date:   Mon Dec 12 15:47:25 2022 -0300

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

    Bugzilla: https://bugzilla.redhat.com/2152571

    CVE: CVE-2022-4378

    Y-Commit: ec2f9f80ba44b533578349a97fb2fe9894142221

    O-Bugzilla: https://bugzilla.redhat.com/2152572

    O-CVE: CVE-2022-4378

    Conflicts: context hunks because out version is much older than

               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: Jarod Wilson <jarod@redhat.com>

Signed-off-by: Ryan Sullivan <rysulliv@redhat.com>

---

 kernel/sysctl.c | 30 +++++++++++++++---------------

 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c

index b4c8a670e9e0..3c8a3a787528 100644

--- a/kernel/sysctl.c

+++ b/kernel/sysctl.c

@@ -2194,13 +2194,14 @@ 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)

@@ -2269,13 +2270,12 @@ 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;

@@ -2438,7 +2438,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,

 		bool neg;

 		if (write) {

-			left -= proc_skip_spaces(&p);

+			proc_skip_spaces(&p, &left);

 			if (!left)

 				break;

@@ -2469,7 +2469,7 @@ 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(&p);

+		proc_skip_spaces(&p, &left);

 	if (write) {

 		kfree(kbuf);

 		if (first)

@@ -2518,7 +2518,7 @@ 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;

@@ -2538,7 +2538,7 @@ 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);

@@ -2982,7 +2982,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int

 		if (write) {

 			bool neg;

-			left -= proc_skip_spaces(&p);

+			proc_skip_spaces(&p, &left);

 			err = proc_get_long(&p, &left, &val, &neg,

 					     proc_wspace_sep,

@@ -3013,7 +3013,7 @@ 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(&p);

+		proc_skip_spaces(&p, &left);

 	if (write) {

 		kfree(kbuf);

 		if (first)

-- 

2.39.2