Message ID | X8ZeAKm8FnFpN//B@mwanda (mailing list archive) |
---|---|
State | Accepted |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | [net,v2] net/x25: prevent a couple of overflows | expand |
Context | Check | Description |
---|---|---|
netdev/cover_letter | success | Link |
netdev/fixes_present | fail | Series targets non-next tree, but doesn't contain any Fixes tags |
netdev/patch_count | success | Link |
netdev/tree_selection | success | Clearly marked for net |
netdev/subject_prefix | success | Link |
netdev/source_inline | success | Was 0 now: 0 |
netdev/verify_signedoff | success | Link |
netdev/module_param | success | Was 0 now: 0 |
netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
netdev/verify_fixes | success | Link |
netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 18 lines checked |
netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
netdev/header_inline | success | Link |
netdev/stable | success | Stable not CCed |
Hi Dan, I think the strnlen is better. the kernel doesn't need to adjust user land mistake by putting a NULL terminator. just return an error to let the user land program fix the wrong address. Regards, kiyin > -----Original Message----- > From: Dan Carpenter [mailto:dan.carpenter@oracle.com] > Sent: Tuesday, December 1, 2020 11:15 PM > To: Martin Schiller <ms@dev.tdt.de> > Cc: David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; > linux-x25@vger.kernel.org; netdev@vger.kernel.org; Andrew Hendry > <andrew.hendry@gmail.com>; kiyin(尹亮) <kiyin@tencent.com>; > security@kernel.org; linux-distros@vs.openwall.org; huntchen(陈阳) > <huntchen@tencent.com>; dannywang(王宇) <dannywang@tencent.com>; > kernel-janitors@vger.kernel.org > Subject: [PATCH net v2] net/x25: prevent a couple of overflows(Internet mail) > > The .x25_addr[] address comes from the user and is not necessarily NUL > terminated. This leads to a couple problems. The first problem is that the > strlen() in x25_bind() can read beyond the end of the buffer. > > The second problem is more subtle and could result in memory corruption. > The call tree is: > x25_connect() > --> x25_write_internal() > --> x25_addr_aton() > > The .x25_addr[] buffers are copied to the "addresses" buffer from > x25_write_internal() so it will lead to stack corruption. > > Verify that the strings are NUL terminated and return -EINVAL if they are not. > > Reported-by: "kiyin(尹亮)" <kiyin@tencent.com> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > The first patch put a NUL terminator on the end of the string and this patch > returns an error instead. I don't have a strong preference, which patch to go > with. > > net/x25/af_x25.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index > 9232cdb42ad9..d41fffb2507b 100644 > --- a/net/x25/af_x25.c > +++ b/net/x25/af_x25.c > @@ -675,7 +675,8 @@ static int x25_bind(struct socket *sock, struct > sockaddr *uaddr, int addr_len) > int len, i, rc = 0; > > if (addr_len != sizeof(struct sockaddr_x25) || > - addr->sx25_family != AF_X25) { > + addr->sx25_family != AF_X25 || > + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == > X25_ADDR_LEN) { > rc = -EINVAL; > goto out; > } > @@ -769,7 +770,8 @@ static int x25_connect(struct socket *sock, struct > sockaddr *uaddr, > > rc = -EINVAL; > if (addr_len != sizeof(struct sockaddr_x25) || > - addr->sx25_family != AF_X25) > + addr->sx25_family != AF_X25 || > + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == > X25_ADDR_LEN) > goto out; > > rc = -ENETUNREACH; > -- > 2.29.2
On 2020-12-01 16:15, Dan Carpenter wrote: > The .x25_addr[] address comes from the user and is not necessarily > NUL terminated. This leads to a couple problems. The first problem is > that the strlen() in x25_bind() can read beyond the end of the buffer. > > The second problem is more subtle and could result in memory > corruption. > The call tree is: > x25_connect() > --> x25_write_internal() > --> x25_addr_aton() > > The .x25_addr[] buffers are copied to the "addresses" buffer from > x25_write_internal() so it will lead to stack corruption. > > Verify that the strings are NUL terminated and return -EINVAL if they > are not. > > Reported-by: "kiyin(尹亮)" <kiyin@tencent.com> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > The first patch put a NUL terminator on the end of the string and this > patch returns an error instead. I don't have a strong preference, > which > patch to go with. > > net/x25/af_x25.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c > index 9232cdb42ad9..d41fffb2507b 100644 > --- a/net/x25/af_x25.c > +++ b/net/x25/af_x25.c > @@ -675,7 +675,8 @@ static int x25_bind(struct socket *sock, struct > sockaddr *uaddr, int addr_len) > int len, i, rc = 0; > > if (addr_len != sizeof(struct sockaddr_x25) || > - addr->sx25_family != AF_X25) { > + addr->sx25_family != AF_X25 || > + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) > { > rc = -EINVAL; > goto out; > } > @@ -769,7 +770,8 @@ static int x25_connect(struct socket *sock, struct > sockaddr *uaddr, > > rc = -EINVAL; > if (addr_len != sizeof(struct sockaddr_x25) || > - addr->sx25_family != AF_X25) > + addr->sx25_family != AF_X25 || > + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) > goto out; > > rc = -ENETUNREACH; Acked-by: Martin Schiller <ms@dev.tdt.de>
On Wed, 02 Dec 2020 10:27:18 +0100 Martin Schiller wrote: > On 2020-12-01 16:15, Dan Carpenter wrote: > > The .x25_addr[] address comes from the user and is not necessarily > > NUL terminated. This leads to a couple problems. The first problem is > > that the strlen() in x25_bind() can read beyond the end of the buffer. > > > > The second problem is more subtle and could result in memory > > corruption. > > The call tree is: > > x25_connect() > > --> x25_write_internal() > > --> x25_addr_aton() > > > > The .x25_addr[] buffers are copied to the "addresses" buffer from > > x25_write_internal() so it will lead to stack corruption. > > > > Verify that the strings are NUL terminated and return -EINVAL if they > > are not. > > > > Reported-by: "kiyin(尹亮)" <kiyin@tencent.com> > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > Acked-by: Martin Schiller <ms@dev.tdt.de> Applied, thanks!
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 9232cdb42ad9..d41fffb2507b 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -675,7 +675,8 @@ static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) int len, i, rc = 0; if (addr_len != sizeof(struct sockaddr_x25) || - addr->sx25_family != AF_X25) { + addr->sx25_family != AF_X25 || + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) { rc = -EINVAL; goto out; } @@ -769,7 +770,8 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr, rc = -EINVAL; if (addr_len != sizeof(struct sockaddr_x25) || - addr->sx25_family != AF_X25) + addr->sx25_family != AF_X25 || + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) goto out; rc = -ENETUNREACH;
The .x25_addr[] address comes from the user and is not necessarily NUL terminated. This leads to a couple problems. The first problem is that the strlen() in x25_bind() can read beyond the end of the buffer. The second problem is more subtle and could result in memory corruption. The call tree is: x25_connect() --> x25_write_internal() --> x25_addr_aton() The .x25_addr[] buffers are copied to the "addresses" buffer from x25_write_internal() so it will lead to stack corruption. Verify that the strings are NUL terminated and return -EINVAL if they are not. Reported-by: "kiyin(尹亮)" <kiyin@tencent.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- The first patch put a NUL terminator on the end of the string and this patch returns an error instead. I don't have a strong preference, which patch to go with. net/x25/af_x25.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)