[syzbot] UBSAN: shift-out-of-bounds in xfrm_set_default

[syzbot] UBSAN: shift-out-of-bounds in xfrm_set_default

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    90d856e71443 Add linux-next specific files for 20210723
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=133fd00a300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=298516715f6ad5cd
dashboard link: https://syzkaller.appspot.com/bug?extid=9cd5837a045bbee5b810
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1263bba6300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1066b4d4300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9cd5837a045bbee5b810@syzkaller.appspotmail.com

netlink: 228 bytes leftover after parsing attributes in process `syz-executor669'.
================================================================================
UBSAN: shift-out-of-bounds in net/xfrm/xfrm_user.c:1969:18
shift exponent 255 is too large for 32-bit type 'int'
CPU: 0 PID: 8437 Comm: syz-executor669 Not tainted 5.14.0-rc2-next-20210723-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327
 xfrm_set_default.cold+0x21/0x102 net/xfrm/xfrm_user.c:1969
 xfrm_user_rcv_msg+0x430/0xa20 net/xfrm/xfrm_user.c:2864
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2886
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43f0d9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc71f859f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043f0d9
RDX: 0000000000000000 RSI: 0000000020000740 RDI: 0000000000000003
RBP: 00000000004030c0 R08: 0000000000000000 R09: 0000000000400488
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403150
R13: 0000000000000000 R14: 00000000004ad018 R15: 0000000000400488
================================================================================


---
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Re: [syzbot] UBSAN: shift-out-of-bounds in xfrm_set_default

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 1256 bytes --]

On Tue, 27 Jul 2021 05:47:21 -0700
syzbot <syzbot+9cd5837a045bbee5b810@syzkaller.appspotmail.com> wrote:

> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    90d856e71443 Add linux-next specific files for
> 20210723 git tree:       linux-next
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=133fd00a300000 kernel
> config:  https://syzkaller.appspot.com/x/.config?x=298516715f6ad5cd
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=9cd5837a045bbee5b810
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU
> Binutils for Debian) 2.35.1 syz repro:
> https://syzkaller.appspot.com/x/repro.syz?x=1263bba6300000 C
> reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1066b4d4300000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the
> commit: Reported-by:
> syzbot+9cd5837a045bbee5b810@syzkaller.appspotmail.com
> 
> netlink: 228 bytes leftover after parsing attributes in process
> `syz-executor669'.
> ================================================================================


The first thing that comes in mind is to check up->dirmask value


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


With regards,
Pavel Skripkin



[-- Attachment #2: 0001-net-xfrm-fix-shift-out-of-bounce.patch --]
[-- Type: text/x-patch, Size: 1152 bytes --]

From 30db223b1f724ca241c7fa15769d0c65eada3b66 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Tue, 27 Jul 2021 17:38:24 +0300
Subject: [PATCH] net: xfrm: fix shift-out-of-bounce

We need to check up->dirmask to avoid shift-out-of-bounce bug,
since up->dirmask comes from userspace.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 net/xfrm/xfrm_user.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index acc3a0dab331..5f3fe2295519 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1966,9 +1966,14 @@ static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct net *net = sock_net(skb->sk);
 	struct xfrm_userpolicy_default *up = nlmsg_data(nlh);
-	u8 dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK;
+	u8 dirmask;
 	u8 old_default = net->xfrm.policy_default;
 
+	if (up->dirmask >= sizeof(up->action) * 8)
+		return -EINVAL;
+
+	dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK
+
 	net->xfrm.policy_default = (old_default & (0xff ^ dirmask))
 				    | (up->action << up->dirmask);
 
-- 
2.32.0

Re: [PATCH] net: xfrm: fix shift-out-of-bounce

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 7530 bytes --]

Hi Pavel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on ipsec-next/master]
[also build test ERROR on next-20210726]
[cannot apply to ipsec/master net-next/master net/master sparc-next/master v5.14-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549
base:   https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git master
config: s390-randconfig-r034-20210727 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project c658b472f3e61e1818e1909bf02f3d65470018a5)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://github.com/0day-ci/linux/commit/0d1cb044926e3d81c86b5add2eeaf38c7aec7f90
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549
        git checkout 0d1cb044926e3d81c86b5add2eeaf38c7aec7f90
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross O=build_dir ARCH=s390 SHELL=/bin/bash net/xfrm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from net/xfrm/xfrm_user.c:22:
   In file included from include/linux/skbuff.h:31:
   In file included from include/linux/dma-mapping.h:10:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __raw_readb(PCI_IOBASE + addr);
                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from macro '__le16_to_cpu'
   #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
                                                             ^
   include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
   #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
                                                        ^
   In file included from net/xfrm/xfrm_user.c:22:
   In file included from include/linux/skbuff.h:31:
   In file included from include/linux/dma-mapping.h:10:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
   #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
                                                             ^
   include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
   #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
                                                        ^
   In file included from net/xfrm/xfrm_user.c:22:
   In file included from include/linux/skbuff.h:31:
   In file included from include/linux/dma-mapping.h:10:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writeb(value, PCI_IOBASE + addr);
                               ~~~~~~~~~~ ^
   include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsb(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsw(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           readsl(PCI_IOBASE + addr, buffer, count);
                  ~~~~~~~~~~ ^
   include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesb(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesw(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
   include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           writesl(PCI_IOBASE + addr, buffer, count);
                   ~~~~~~~~~~ ^
>> net/xfrm/xfrm_user.c:1975:54: error: expected ';' after expression
           dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK
                                                               ^
                                                               ;
   12 warnings and 1 error generated.


vim +1975 net/xfrm/xfrm_user.c

  1963	
  1964	static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,
  1965				    struct nlattr **attrs)
  1966	{
  1967		struct net *net = sock_net(skb->sk);
  1968		struct xfrm_userpolicy_default *up = nlmsg_data(nlh);
  1969		u8 dirmask;
  1970		u8 old_default = net->xfrm.policy_default;
  1971	
  1972		if (up->dirmask >= sizeof(up->action) * 8)
  1973			return -EINVAL;
  1974	
> 1975		dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK
  1976	
  1977		net->xfrm.policy_default = (old_default & (0xff ^ dirmask))
  1978					    | (up->action << up->dirmask);
  1979	
  1980		rt_genid_bump_all(net);
  1981	
  1982		return 0;
  1983	}
  1984	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 16790 bytes --]

Re: [PATCH] net: xfrm: fix shift-out-of-bounce

[Pavel Skripkin]

[-- Attachment #1: Type: text/plain, Size: 6212 bytes --]

On Wed, 28 Jul 2021 01:25:18 +0800
kernel test robot <lkp@intel.com> wrote:

> Hi Pavel,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on ipsec-next/master]
> [also build test ERROR on next-20210726]
> [cannot apply to ipsec/master net-next/master net/master
> sparc-next/master v5.14-rc3] [If your patch is applied to the wrong
> git tree, kindly drop us a note. And when submitting patch, we
> suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:
> https://github.com/0day-ci/linux/commits/Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549
> base:
> https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git
> master config: s390-randconfig-r034-20210727 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
> c658b472f3e61e1818e1909bf02f3d65470018a5) reproduce (this is a W=1
> build): wget
> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
> -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross
> compiling tool for clang build # apt-get install
> binutils-s390x-linux-gnu #
> https://github.com/0day-ci/linux/commit/0d1cb044926e3d81c86b5add2eeaf38c7aec7f90
> git remote add linux-review https://github.com/0day-ci/linux git
> fetch --no-tags linux-review
> Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549 git
> checkout 0d1cb044926e3d81c86b5add2eeaf38c7aec7f90 # save the attached
> .config to linux build tree mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
> O=build_dir ARCH=s390 SHELL=/bin/bash net/xfrm/
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from net/xfrm/xfrm_user.c:22:
>    In file included from include/linux/skbuff.h:31:
>    In file included from include/linux/dma-mapping.h:10:
>    In file included from include/linux/scatterlist.h:9:
>    In file included from arch/s390/include/asm/io.h:75:
>    include/asm-generic/io.h:464:31: warning: performing pointer
> arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr);
> ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing
> pointer arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16
> __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^
> include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from
> macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force
> __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded
> from macro '__swab16' #define __swab16(x)
> (__u16)__builtin_bswap16((__u16)(x)) ^
>    In file included from net/xfrm/xfrm_user.c:22:
>    In file included from include/linux/skbuff.h:31:
>    In file included from include/linux/dma-mapping.h:10:
>    In file included from include/linux/scatterlist.h:9:
>    In file included from arch/s390/include/asm/io.h:75:
>    include/asm-generic/io.h:490:61: warning: performing pointer
> arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32
> __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^
> include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from
> macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force
> __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded
> from macro '__swab32' #define __swab32(x)
> (__u32)__builtin_bswap32((__u32)(x)) ^
>    In file included from net/xfrm/xfrm_user.c:22:
>    In file included from include/linux/skbuff.h:31:
>    In file included from include/linux/dma-mapping.h:10:
>    In file included from include/linux/scatterlist.h:9:
>    In file included from arch/s390/include/asm/io.h:75:
>    include/asm-generic/io.h:501:33: warning: performing pointer
> arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr);
> ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing
> pointer arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] __raw_writew((u16
> __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^
> include/asm-generic/io.h:521:59: warning: performing pointer
> arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] __raw_writel((u32
> __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^
> include/asm-generic/io.h:609:20: warning: performing pointer
> arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing
> pointer arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing
> pointer arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count);
> ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing
> pointer arithmetic on a null pointer has undefined behavior
> [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer,
> count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning:
> performing pointer arithmetic on a null pointer has undefined
> behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr,
> buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21:
> warning: performing pointer arithmetic on a null pointer has
> undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE +
> addr, buffer, count); ~~~~~~~~~~ ^
> >> net/xfrm/xfrm_user.c:1975:54: error: expected ';' after expression
>            dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK
>                                                                ^
>                                                                ;

Oops :) Thank you, kernel test robot.

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


With regards,
Pavel Skripkin



[-- Attachment #2: 0001-net-xfrm-fix-shift-out-of-bounce.patch --]
[-- Type: text/x-patch, Size: 1153 bytes --]

From e7cf3838979bf3079a511b6809e971945f50eb25 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Tue, 27 Jul 2021 17:38:24 +0300
Subject: [PATCH] net: xfrm: fix shift-out-of-bounce

We need to check up->dirmask to avoid shift-out-of-bounce bug,
since up->dirmask comes from userspace.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 net/xfrm/xfrm_user.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index acc3a0dab331..4a7bb169314e 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1966,9 +1966,14 @@ static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct net *net = sock_net(skb->sk);
 	struct xfrm_userpolicy_default *up = nlmsg_data(nlh);
-	u8 dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK;
+	u8 dirmask;
 	u8 old_default = net->xfrm.policy_default;
 
+	if (up->dirmask >= sizeof(up->action) * 8)
+		return -EINVAL;
+
+	dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK;
+
 	net->xfrm.policy_default = (old_default & (0xff ^ dirmask))
 				    | (up->action << up->dirmask);
 
-- 
2.32.0

Re: [PATCH] net: xfrm: fix shift-out-of-bounce

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4205 bytes --]

Hi Pavel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on ipsec-next/master]
[also build test ERROR on next-20210726]
[cannot apply to ipsec/master net-next/master net/master v5.14-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549
base:   https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git master
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 10.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/0d1cb044926e3d81c86b5add2eeaf38c7aec7f90
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Pavel-Skripkin/net-xfrm-fix-shift-out-of-bounce/20210727-224549
        git checkout 0d1cb044926e3d81c86b5add2eeaf38c7aec7f90
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross O=build_dir ARCH=sh SHELL=/bin/bash net/xfrm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   net/xfrm/xfrm_user.c: In function 'xfrm_set_default':
>> net/xfrm/xfrm_user.c:1977:2: error: expected ';' before 'net'
    1977 |  net->xfrm.policy_default = (old_default & (0xff ^ dirmask))
         |  ^~~
   net/xfrm/xfrm_user.c:1970:5: warning: unused variable 'old_default' [-Wunused-variable]
    1970 |  u8 old_default = net->xfrm.policy_default;
         |     ^~~~~~~~~~~
>> net/xfrm/xfrm_user.c:1969:5: warning: variable 'dirmask' set but not used [-Wunused-but-set-variable]
    1969 |  u8 dirmask;
         |     ^~~~~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
   Depends on SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && HAS_DMA
   Selected by
   - SND_ATMEL_SOC_SSC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC
   - SND_ATMEL_SOC_SSC_PDC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && ATMEL_SSC


vim +1977 net/xfrm/xfrm_user.c

^1da177e4c3f41 Linus Torvalds   2005-04-16  1963  
2d151d39073aff Steffen Klassert 2021-07-18  1964  static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,
2d151d39073aff Steffen Klassert 2021-07-18  1965  			    struct nlattr **attrs)
2d151d39073aff Steffen Klassert 2021-07-18  1966  {
2d151d39073aff Steffen Klassert 2021-07-18  1967  	struct net *net = sock_net(skb->sk);
2d151d39073aff Steffen Klassert 2021-07-18  1968  	struct xfrm_userpolicy_default *up = nlmsg_data(nlh);
0d1cb044926e3d Pavel Skripkin   2021-07-27 @1969  	u8 dirmask;
2d151d39073aff Steffen Klassert 2021-07-18  1970  	u8 old_default = net->xfrm.policy_default;
2d151d39073aff Steffen Klassert 2021-07-18  1971  
0d1cb044926e3d Pavel Skripkin   2021-07-27  1972  	if (up->dirmask >= sizeof(up->action) * 8)
0d1cb044926e3d Pavel Skripkin   2021-07-27  1973  		return -EINVAL;
0d1cb044926e3d Pavel Skripkin   2021-07-27  1974  
0d1cb044926e3d Pavel Skripkin   2021-07-27  1975  	dirmask = (1 << up->dirmask) & XFRM_POL_DEFAULT_MASK
0d1cb044926e3d Pavel Skripkin   2021-07-27  1976  
2d151d39073aff Steffen Klassert 2021-07-18 @1977  	net->xfrm.policy_default = (old_default & (0xff ^ dirmask))
2d151d39073aff Steffen Klassert 2021-07-18  1978  				    | (up->action << up->dirmask);
2d151d39073aff Steffen Klassert 2021-07-18  1979  
2d151d39073aff Steffen Klassert 2021-07-18  1980  	rt_genid_bump_all(net);
2d151d39073aff Steffen Klassert 2021-07-18  1981  
2d151d39073aff Steffen Klassert 2021-07-18  1982  	return 0;
2d151d39073aff Steffen Klassert 2021-07-18  1983  }
2d151d39073aff Steffen Klassert 2021-07-18  1984  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [syzbot] UBSAN: shift-out-of-bounds in xfrm_set_default

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

net/xfrm/xfrm_user.c:1977:2: error: expected ';' before 'net'


Tested on:

commit:         42d0b5f5 Add linux-next specific files for 20210727
git tree:       linux-next
dashboard link: https://syzkaller.appspot.com/bug?extid=9cd5837a045bbee5b810
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=147b8d0a300000

Re: [syzbot] UBSAN: shift-out-of-bounds in xfrm_set_default

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+9cd5837a045bbee5b810@syzkaller.appspotmail.com

Tested on:

commit:         42d0b5f5 Add linux-next specific files for 20210727
git tree:       linux-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=e5bd567a6f50f462
dashboard link: https://syzkaller.appspot.com/bug?extid=9cd5837a045bbee5b810
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1204e0dc300000

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