[syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    48e8992e33ab Add linux-next specific files for 20231213
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=155c1ac1e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=978b8aaa2e92a8f
dashboard link: https://syzkaller.appspot.com/bug?extid=94bbb75204a05da3d89f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10e0a966e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1555a15ce80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ade5327f8151/disk-48e8992e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/16bff810e759/vmlinux-48e8992e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/14c4448589de/bzImage-48e8992e.xz

The issue was bisected to:

commit b946001d3bb1202e90093cf5e72dbcb20e2689a0
Author: David Howells <dhowells@redhat.com>
Date:   Sat Dec 9 00:41:55 2023 +0000

    keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10c349c1e80000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=12c349c1e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=14c349c1e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")

==================================================================
BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
Read of size 1 at addr ffff888028894084 by task syz-executor265/5069

CPU: 0 PID: 5069 Comm: syz-executor265 Not tainted 6.7.0-rc5-next-20231213-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
 __key_create_or_update+0x453/0xdf0 security/keys/key.c:842
 key_create_or_update+0x42/0x50 security/keys/key.c:1007
 __do_sys_add_key+0x29c/0x450 security/keys/keyctl.c:134
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7fd37f34f2e9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff2f4f3198 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00007fff2f4f3368 RCX: 00007fd37f34f2e9
RDX: 0000000020000080 RSI: 0000000000000000 RDI: 00000000200003c0
RBP: 00007fd37f3c2610 R08: 0000000002853c32 R09: 00007fff2f4f3368
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff2f4f3358 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Allocated by task 5069:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
 kasan_set_track+0x24/0x30 mm/kasan/common.c:61
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slub.c:3985 [inline]
 __kmalloc_node+0x226/0x480 mm/slub.c:3992
 kmalloc_node include/linux/slab.h:610 [inline]
 kvmalloc_node+0x99/0x1a0 mm/util.c:617
 kvmalloc include/linux/slab.h:728 [inline]
 __do_sys_add_key+0x1f8/0x450 security/keys/keyctl.c:116
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x62/0x6a

The buggy address belongs to the object at ffff888028894080
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
 allocated 4-byte region [ffff888028894080, ffff888028894084)

The buggy address belongs to the physical page:
page:ffffea0000a22500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28894
anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888013041280 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080800080 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 27978623390, free_ts 27978121808
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1540
 prep_new_page mm/page_alloc.c:1547 [inline]
 get_page_from_freelist+0xa19/0x3740 mm/page_alloc.c:3355
 __alloc_pages+0x22e/0x2410 mm/page_alloc.c:4611
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 alloc_slab_page mm/slub.c:2191 [inline]
 allocate_slab mm/slub.c:2358 [inline]
 new_slab+0x283/0x3c0 mm/slub.c:2411
 ___slab_alloc+0x4ab/0x1990 mm/slub.c:3544
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3629
 __slab_alloc_node mm/slub.c:3682 [inline]
 slab_alloc_node mm/slub.c:3854 [inline]
 __do_kmalloc_node mm/slub.c:3984 [inline]
 __kmalloc_node_track_caller+0x367/0x470 mm/slub.c:4005
 kstrdup+0x3c/0x70 mm/util.c:62
 kstrdup_const+0x5f/0x70 mm/util.c:85
 kvasprintf_const+0x10b/0x190 lib/kasprintf.c:48
 kobject_set_name_vargs+0x5a/0x130 lib/kobject.c:272
 kobject_add_varg lib/kobject.c:366 [inline]
 kobject_init_and_add+0xe8/0x190 lib/kobject.c:455
 locate_module_kobject+0xef/0x190 kernel/params.c:781
 kernel_add_sysfs_param kernel/params.c:808 [inline]
 param_sysfs_builtin kernel/params.c:856 [inline]
 param_sysfs_builtin_init+0x25f/0x450 kernel/params.c:990
 do_one_initcall+0x128/0x680 init/main.c:1236
page last free pid 3062 tgid 3062 stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1140 [inline]
 free_unref_page_prepare+0x51f/0xb10 mm/page_alloc.c:2390
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2530
 mm_free_pgd kernel/fork.c:799 [inline]
 __mmdrop+0xd5/0x470 kernel/fork.c:915
 mmdrop include/linux/sched/mm.h:54 [inline]
 __mmput+0x40a/0x4d0 kernel/fork.c:1352
 mmput+0x62/0x70 kernel/fork.c:1363
 free_bprm+0x143/0x3e0 fs/exec.c:1490
 kernel_execve+0x3e6/0x4e0 fs/exec.c:2036
 call_usermodehelper_exec_async+0x252/0x4c0 kernel/umh.c:110
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Memory state around the buggy address:
 ffff888028893f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888028894000: 07 fc fc fc 07 fc fc fc fa fc fc fc 05 fc fc fc
>ffff888028894080: 04 fc fc fc fb fc fc fc fb fc fc fc 06 fc fc fc
                   ^
 ffff888028894100: 06 fc fc fc fb fc fc fc 00 fc fc fc 00 fc fc fc
 ffff888028894180: fb fc fc fc 04 fc fc fc 04 fc fc fc fb fc fc fc
==================================================================


---
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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#syz undup

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse
Author: eadavis@qq.com

please test slab-out-of-bounds Read in dns_resolver_preparse

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 48e8992e33ab
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 10ba439968f7..f28ba8a703fe 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -83,7 +83,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
 	long ret;
 
 	ret = -EINVAL;
-	if (plen > 1024 * 1024 - 1)
+	if (plen > 1024 * 1024 - 1 || plen < 48)
 		goto error;
 
 	/* draw all the data into kernel space */

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse
Author: eadavis@qq.com

please test slab-out-of-bounds Read in dns_resolver_preparse

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 48e8992e33ab
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 3233f4f25fed..15f19521021c 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 
 	if (data[0] == 0) {
 		/* It may be a server list. */
-		if (datalen <= sizeof(*bin))
+		if (datalen <= sizeof(*v1))
 			return -EINVAL;
 
 		bin = (const struct dns_payload_header *)data;

[PATCH next] keys/dns: datalen must greater than sizeof(*v1)

[Edward Adam Davis]

bin will be forcibly converted to "struct dns_server_list_v1_header *", so it 
is necessary to compare datalen with sizeof(*v1).

Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 net/dns_resolver/dns_key.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 3233f4f25fed..15f19521021c 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 
 	if (data[0] == 0) {
 		/* It may be a server list. */
-		if (datalen <= sizeof(*bin))
+		if (datalen <= sizeof(*v1))
 			return -EINVAL;
 
 		bin = (const struct dns_payload_header *)data;

[PATCH V2 next] keys/dns: fix slab-out-of-bounds in dns_resolver_preparse

[Edward Adam Davis]

bin will be forcibly converted to "struct dns_server_list_v1_header *", so it 
is necessary to compare datalen with sizeof(*v1).

Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 net/dns_resolver/dns_key.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 3233f4f25fed..15f19521021c 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 
 	if (data[0] == 0) {
 		/* It may be a server list. */
-		if (datalen <= sizeof(*bin))
+		if (datalen <= sizeof(*v1))
 			return -EINVAL;
 
 		bin = (const struct dns_payload_header *)data;
-- 
2.43.0

Re: [PATCH next] keys/dns: datalen must greater than sizeof(*v1)

[Jarkko Sakkinen]

On Thu Dec 14, 2023 at 4:33 PM EET, Edward Adam Davis wrote:
> bin will be forcibly converted to "struct dns_server_list_v1_header *", so it 
> is necessary to compare datalen with sizeof(*v1).
>
> Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
> Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  net/dns_resolver/dns_key.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
> index 3233f4f25fed..15f19521021c 100644
> --- a/net/dns_resolver/dns_key.c
> +++ b/net/dns_resolver/dns_key.c
> @@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
>  
>  	if (data[0] == 0) {
>  		/* It may be a server list. */
> -		if (datalen <= sizeof(*bin))
> +		if (datalen <= sizeof(*v1))
>  			return -EINVAL;
>  
>  		bin = (const struct dns_payload_header *)data;

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

Re: [PATCH V2 next] keys/dns: fix slab-out-of-bounds in dns_resolver_preparse

[Simon Horman]

On Thu, Dec 14, 2023 at 10:46:10PM +0800, Edward Adam Davis wrote:
> bin will be forcibly converted to "struct dns_server_list_v1_header *", so it 
> is necessary to compare datalen with sizeof(*v1).
> 
> Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
> Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  net/dns_resolver/dns_key.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

This change looks correct to me.
And I agree that it addresses a problem introduced by the cited commit.
I also note that it depends on the cited commit, which is not present in net.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[David Howells]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 2a6d363763a2..f18ca02aa95a 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -91,8 +91,6 @@ const struct cred *dns_resolver_cache;
 static int
 dns_resolver_preparse(struct key_preparsed_payload *prep)
 {
-	const struct dns_server_list_v1_header *v1;
-	const struct dns_payload_header *bin;
 	struct user_key_payload *upayload;
 	unsigned long derrno;
 	int ret;
@@ -103,27 +101,28 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 		return -EINVAL;
 
 	if (data[0] == 0) {
+		const struct dns_server_list_v1_header *v1;
+
 		/* It may be a server list. */
-		if (datalen <= sizeof(*bin))
+		if (datalen <= sizeof(*v1))
 			return -EINVAL;
 
-		bin = (const struct dns_payload_header *)data;
-		kenter("[%u,%u],%u", bin->content, bin->version, datalen);
-		if (bin->content != DNS_PAYLOAD_IS_SERVER_LIST) {
+		v1 = (const struct dns_server_list_v1_header *)data;
+		kenter("[%u,%u],%u", v1->hdr.content, v1->hdr.version, datalen);
+		if (v1->hdr.content != DNS_PAYLOAD_IS_SERVER_LIST) {
 			pr_warn_ratelimited(
 				"dns_resolver: Unsupported content type (%u)\n",
-				bin->content);
+				v1->hdr.content);
 			return -EINVAL;
 		}
 
-		if (bin->version != 1) {
+		if (v1->hdr.version != 1) {
 			pr_warn_ratelimited(
 				"dns_resolver: Unsupported server list version (%u)\n",
-				bin->version);
+				v1->hdr.version);
 			return -EINVAL;
 		}
 
-		v1 = (const struct dns_server_list_v1_header *)bin;
 		if ((v1->status != DNS_LOOKUP_GOOD &&
 		     v1->status != DNS_LOOKUP_GOOD_WITH_BAD)) {
 			if (prep->expiry == TIME64_MAX)

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot]

> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

want either no args or 2 args (repo, branch), got 5

>
> diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
> index 2a6d363763a2..f18ca02aa95a 100644
> --- a/net/dns_resolver/dns_key.c
> +++ b/net/dns_resolver/dns_key.c
> @@ -91,8 +91,6 @@ const struct cred *dns_resolver_cache;
>  static int
>  dns_resolver_preparse(struct key_preparsed_payload *prep)
>  {
> -	const struct dns_server_list_v1_header *v1;
> -	const struct dns_payload_header *bin;
>  	struct user_key_payload *upayload;
>  	unsigned long derrno;
>  	int ret;
> @@ -103,27 +101,28 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
>  		return -EINVAL;
>  
>  	if (data[0] == 0) {
> +		const struct dns_server_list_v1_header *v1;
> +
>  		/* It may be a server list. */
> -		if (datalen <= sizeof(*bin))
> +		if (datalen <= sizeof(*v1))
>  			return -EINVAL;
>  
> -		bin = (const struct dns_payload_header *)data;
> -		kenter("[%u,%u],%u", bin->content, bin->version, datalen);
> -		if (bin->content != DNS_PAYLOAD_IS_SERVER_LIST) {
> +		v1 = (const struct dns_server_list_v1_header *)data;
> +		kenter("[%u,%u],%u", v1->hdr.content, v1->hdr.version, datalen);
> +		if (v1->hdr.content != DNS_PAYLOAD_IS_SERVER_LIST) {
>  			pr_warn_ratelimited(
>  				"dns_resolver: Unsupported content type (%u)\n",
> -				bin->content);
> +				v1->hdr.content);
>  			return -EINVAL;
>  		}
>  
> -		if (bin->version != 1) {
> +		if (v1->hdr.version != 1) {
>  			pr_warn_ratelimited(
>  				"dns_resolver: Unsupported server list version (%u)\n",
> -				bin->version);
> +				v1->hdr.version);
>  			return -EINVAL;
>  		}
>  
> -		v1 = (const struct dns_server_list_v1_header *)bin;
>  		if ((v1->status != DNS_LOOKUP_GOOD &&
>  		     v1->status != DNS_LOOKUP_GOOD_WITH_BAD)) {
>  			if (prep->expiry == TIME64_MAX)
>

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[David Howells]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index 2a6d363763a2..f18ca02aa95a 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -91,8 +91,6 @@ const struct cred *dns_resolver_cache;
 static int
 dns_resolver_preparse(struct key_preparsed_payload *prep)
 {
-	const struct dns_server_list_v1_header *v1;
-	const struct dns_payload_header *bin;
 	struct user_key_payload *upayload;
 	unsigned long derrno;
 	int ret;
@@ -103,27 +101,28 @@ dns_resolver_preparse(struct key_preparsed_payload *prep)
 		return -EINVAL;
 
 	if (data[0] == 0) {
+		const struct dns_server_list_v1_header *v1;
+
 		/* It may be a server list. */
-		if (datalen <= sizeof(*bin))
+		if (datalen <= sizeof(*v1))
 			return -EINVAL;
 
-		bin = (const struct dns_payload_header *)data;
-		kenter("[%u,%u],%u", bin->content, bin->version, datalen);
-		if (bin->content != DNS_PAYLOAD_IS_SERVER_LIST) {
+		v1 = (const struct dns_server_list_v1_header *)data;
+		kenter("[%u,%u],%u", v1->hdr.content, v1->hdr.version, datalen);
+		if (v1->hdr.content != DNS_PAYLOAD_IS_SERVER_LIST) {
 			pr_warn_ratelimited(
 				"dns_resolver: Unsupported content type (%u)\n",
-				bin->content);
+				v1->hdr.content);
 			return -EINVAL;
 		}
 
-		if (bin->version != 1) {
+		if (v1->hdr.version != 1) {
 			pr_warn_ratelimited(
 				"dns_resolver: Unsupported server list version (%u)\n",
-				bin->version);
+				v1->hdr.version);
 			return -EINVAL;
 		}
 
-		v1 = (const struct dns_server_list_v1_header *)bin;
 		if ((v1->status != DNS_LOOKUP_GOOD &&
 		     v1->status != DNS_LOOKUP_GOOD_WITH_BAD)) {
 			if (prep->expiry == TIME64_MAX)

Re: [syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com

Tested on:

commit:         3f82f1c3 Merge tag 'x86-urgent-2023-12-23' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=132be7e9e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9f7c7b3fa354ead9
dashboard link: https://syzkaller.appspot.com/bug?extid=94bbb75204a05da3d89f
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15ef6e26e80000

Note: testing is done by a robot and is best-effort only.