Test WARNING in __vunmap

[Khalid Masum]

#syz-test: https://github.com/torvalds/linux.git b90cb1053190
Reported-by: syzbot+5ec9bb...@syzkaller.appspotmail.com
link: https://lore.kernel.org/lkml/00000000000092...@google.com/
---

net/xfrm/xfrm_ipcomp.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index cb40ff0ff28d..0c60ccecb55f 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -210,12 +210,16 @@ static void * __percpu *ipcomp_alloc_scratches(void)
void * __percpu *scratches;
int i;

- if (ipcomp_scratch_users++)
+ if (ipcomp_scratch_users) {
+ ipcomp_scratch_users++;
return ipcomp_scratches;
-
+ }
scratches = alloc_percpu(void *);
- if (!scratches)
+ if (!scratches){
+ ipcomp_scratches = NULL;
return NULL;
+ }
+ ipcomp_scratch_users++;

ipcomp_scratches = scratches;

--
2.37.1

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17680f95080000
kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=17447493080000

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

[Khalid Masum]

#syz-test: https://github.com/torvalds/linux.git b90cb1053190
Reported-by: syzbot+5ec9bb...@syzkaller.appspotmail.com
link: https://lore.kernel.org/lkml/00000000000092...@google.com/

---

net/xfrm/xfrm_ipcomp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index cb40ff0ff28d..af9097983139 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -210,13 +210,15 @@ static void * __percpu *ipcomp_alloc_scratches(void)

void * __percpu *scratches;
int i;

- if (ipcomp_scratch_users++)
+ if (ipcomp_scratch_users) {
+ ipcomp_scratch_users++;
return ipcomp_scratches;
-
+ }
scratches = alloc_percpu(void *);

if (!scratches)
return NULL;

+ ipcomp_scratch_users++;
ipcomp_scratches = scratches;

for_each_possible_cpu(i) {
--
2.37.1

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=130b9783080000

kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=131da07d080000

[Khalid Masum]

#syz-test: https://github.com/torvalds/linux.git b90cb1053190
Reported-by: syzbot+5ec9bb...@syzkaller.appspotmail.com
link: https://lore.kernel.org/lkml/00000000000092...@google.com/
---

diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index cb40ff0ff28d..17815cde8a7f 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -215,7 +215,7 @@ static void * __percpu *ipcomp_alloc_scratches(void)

scratches = alloc_percpu(void *);
if (!scratches)

- return NULL;
+ return ipcomp_scratches = NULL;

ipcomp_scratches = scratches;

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=103c046d080000

kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=121bdb75080000

[Khalid Masum]

#syz-test: https://github.com/torvalds/linux.git b90cb1053190
Reported-by: syzbot+5ec9bb...@syzkaller.appspotmail.com
link: https://lore.kernel.org/lkml/00000000000092...@google.com/
---
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c

index cb40ff0ff28d..7f3cbd941eb6 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -31,7 +31,7 @@ struct ipcomp_tfms {
};

static DEFINE_MUTEX(ipcomp_resource_mutex);
-static void * __percpu *ipcomp_scratches;
+static void * __percpu *ipcomp_scratches = NULL;
static int ipcomp_scratch_users;
static LIST_HEAD(ipcomp_tfms_list);

@@ -203,6 +203,7 @@ static void ipcomp_free_scratches(void)
vfree(*per_cpu_ptr(scratches, i));

free_percpu(scratches);
+ ipcomp_scratches = NULL;

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=10634b33080000

kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=136c90cd080000

[Khalid Masum]

#syz-test: https://github.com/torvalds/linux.git b90cb1053190
Reported-by: syzbot+5ec9bb...@syzkaller.appspotmail.com
link: https://lore.kernel.org/lkml/00000000000092...@google.com/
---

diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index cb40ff0ff28d..3774d07c5819 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c

@@ -203,6 +203,7 @@ static void ipcomp_free_scratches(void)
vfree(*per_cpu_ptr(scratches, i));

free_percpu(scratches);
+ ipcomp_scratches = NULL;
}

static void * __percpu *ipcomp_alloc_scratches(void)

@@ -215,7 +216,7 @@ static void * __percpu *ipcomp_alloc_scratches(void)

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=161660ab080000

kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=1360a8ab080000

[Khalid Masum]

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+5ec9bb...@syzkaller.appspotmail.com

Tested on:

commit: b90cb105 Linux 6.0-rc3
git tree: https://github.com/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=13fd306d080000

kernel config: https://syzkaller.appspot.com/x/.config?x=7a83b0ed0cc4e36e
dashboard link: https://syzkaller.appspot.com/bug?extid=5ec9bb042ddfe9644773
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=15d5be63080000

[Dan Carpenter]

Heh. You have inspired me to create a static checker warning so that
no one writes code like this in the future. :P Write it as:

if (!scratches) {

ipcomp_scratches = NULL;
return NULL;
}

regards,
dan carpenter

[Khalid Masum]

Thanks for the tip. Are you adding this warning for checkpatch.pl?
-- Khalid Masum