| Message ID | 20200616032524.460144-3-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add seccomp notifier ioctl that enables adding fds | expand |
On Mon, Jun 15, 2020 at 08:25:15PM -0700, Kees Cook wrote: > In preparation for users of the "install a received file" logic outside > of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from > net/core/scm.c to __fd_install_received() in fs/file.c, and provide a > wrapper named fd_install_received_user(), as future patches will change > the interface to __fd_install_received(). > > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > fs/file.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/file.h | 8 ++++++++ > include/net/scm.h | 1 - > net/compat.c | 2 +- > net/core/scm.c | 32 +----------------------------- > 5 files changed, 57 insertions(+), 33 deletions(-) > > diff --git a/fs/file.c b/fs/file.c > index abb8b7081d7a..fcfddae0d252 100644 > --- a/fs/file.c > +++ b/fs/file.c > @@ -11,6 +11,7 @@ > #include <linux/export.h> > #include <linux/fs.h> > #include <linux/mm.h> > +#include <linux/net.h> > #include <linux/sched/signal.h> > #include <linux/slab.h> > #include <linux/file.h> > @@ -18,6 +19,8 @@ > #include <linux/bitops.h> > #include <linux/spinlock.h> > #include <linux/rcupdate.h> > +#include <net/cls_cgroup.h> > +#include <net/netprio_cgroup.h> > > unsigned int sysctl_nr_open __read_mostly = 1024*1024; > unsigned int sysctl_nr_open_min = BITS_PER_LONG; > @@ -931,6 +934,50 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) > return err; > } > > +/** > + * __fd_install_received() - Install received file into file descriptor table > + * > + * @fd: fd to install into (if negative, a new fd will be allocated) > + * @file: struct file that was received from another process > + * @ufd_required: true to use @ufd for writing fd number to userspace > + * @ufd: __user pointer to write new fd number to > + * @o_flags: the O_* flags to apply to the new fd entry Probably doesn't matter, but this function doesn't take the fd, or ufd_required argument in this patch. > + * > + * Installs a received file into the file descriptor table, with appropriate > + * checks and count updates. Optionally writes the fd number to userspace. ufd does not apppear options here. > + * > + * Returns -ve on error. > + */ > +int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags) > +{ > + struct socket *sock; > + int new_fd; > + int error; > + > + error = security_file_receive(file); > + if (error) > + return error; > + > + new_fd = get_unused_fd_flags(o_flags); > + if (new_fd < 0) > + return new_fd; > + > + error = put_user(new_fd, ufd); > + if (error) { > + put_unused_fd(new_fd); > + return error; > + } > + > + /* Bump the usage count and install the file. */ > + sock = sock_from_file(file, &error); > + if (sock) { > + sock_update_netprioidx(&sock->sk->sk_cgrp_data); > + sock_update_classid(&sock->sk->sk_cgrp_data); > + } > + fd_install(new_fd, get_file(file)); > + return 0; > +} > + > static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) > { > int err = -EBADF; > diff --git a/include/linux/file.h b/include/linux/file.h > index 122f80084a3e..fe18a1a0d555 100644 > --- a/include/linux/file.h > +++ b/include/linux/file.h > @@ -91,6 +91,14 @@ extern void put_unused_fd(unsigned int fd); > > extern void fd_install(unsigned int fd, struct file *file); > > +extern int __fd_install_received(struct file *file, int __user *ufd, > + unsigned int o_flags); > +static inline int fd_install_received_user(struct file *file, int __user *ufd, > + unsigned int o_flags) > +{ > + return __fd_install_received(file, ufd, o_flags); > +} > + > extern void flush_delayed_fput(void); > extern void __fput_sync(struct file *); > > diff --git a/include/net/scm.h b/include/net/scm.h > index 581a94d6c613..1ce365f4c256 100644 > --- a/include/net/scm.h > +++ b/include/net/scm.h > @@ -37,7 +37,6 @@ struct scm_cookie { > #endif > }; > > -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags); > void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); > void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); > int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); > diff --git a/net/compat.c b/net/compat.c > index 27d477fdcaa0..94f288e8dac5 100644 > --- a/net/compat.c > +++ b/net/compat.c > @@ -298,7 +298,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) > int err = 0, i; > > for (i = 0; i < fdmax; i++) { > - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); > + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); > if (err) > break; > } > diff --git a/net/core/scm.c b/net/core/scm.c > index 6151678c73ed..df190f1fdd28 100644 > --- a/net/core/scm.c > +++ b/net/core/scm.c > @@ -280,36 +280,6 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter > } > EXPORT_SYMBOL(put_cmsg_scm_timestamping); > > -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags) > -{ > - struct socket *sock; > - int new_fd; > - int error; > - > - error = security_file_receive(file); > - if (error) > - return error; > - > - new_fd = get_unused_fd_flags(o_flags); > - if (new_fd < 0) > - return new_fd; > - > - error = put_user(new_fd, ufd); > - if (error) { > - put_unused_fd(new_fd); > - return error; > - } > - > - /* Bump the usage count and install the file. */ > - sock = sock_from_file(file, &error); > - if (sock) { > - sock_update_netprioidx(&sock->sk->sk_cgrp_data); > - sock_update_classid(&sock->sk->sk_cgrp_data); > - } > - fd_install(new_fd, get_file(file)); > - return 0; > -} > - > static int scm_max_fds(struct msghdr *msg) > { > if (msg->msg_controllen <= sizeof(struct cmsghdr)) > @@ -336,7 +306,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) > } > > for (i = 0; i < fdmax; i++) { > - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); > + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); > if (err) > break; > } > -- > 2.25.1 >
On Tue, Jun 16, 2020 at 05:29:41AM +0000, Sargun Dhillon wrote: > On Mon, Jun 15, 2020 at 08:25:15PM -0700, Kees Cook wrote: > > +/** > > + * __fd_install_received() - Install received file into file descriptor table > > + * > > + * @fd: fd to install into (if negative, a new fd will be allocated) > > + * @file: struct file that was received from another process > > + * @ufd_required: true to use @ufd for writing fd number to userspace > > + * @ufd: __user pointer to write new fd number to > > + * @o_flags: the O_* flags to apply to the new fd entry > Probably doesn't matter, but this function doesn't take the fd, or ufd_required > argument in this patch. > > > + * > > + * Installs a received file into the file descriptor table, with appropriate > > + * checks and count updates. Optionally writes the fd number to userspace. > ufd does not apppear options here. Argh, yes, thanks. I think this was a fixup targeting the wrong commit. I will adjust.
From: Kees Cook > Sent: 16 June 2020 04:25 > In preparation for users of the "install a received file" logic outside > of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from > net/core/scm.c to __fd_install_received() in fs/file.c, and provide a > wrapper named fd_install_received_user(), as future patches will change > the interface to __fd_install_received(). Any reason for the leading __ ?? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Wed, Jun 17, 2020 at 03:25:41PM +0000, David Laight wrote: > From: Kees Cook > > Sent: 16 June 2020 04:25 > > > In preparation for users of the "install a received file" logic outside > > of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from > > net/core/scm.c to __fd_install_received() in fs/file.c, and provide a > > wrapper named fd_install_received_user(), as future patches will change > > the interface to __fd_install_received(). > > Any reason for the leading __ ?? Mainly because of the code pattern of only using the inline helpers to call it.
On Mon, Jun 15, 2020 at 08:25:15PM -0700, Kees Cook wrote: > In preparation for users of the "install a received file" logic outside > of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from > net/core/scm.c to __fd_install_received() in fs/file.c, and provide a > wrapper named fd_install_received_user(), as future patches will change > the interface to __fd_install_received(). > > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > fs/file.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/file.h | 8 ++++++++ > include/net/scm.h | 1 - > net/compat.c | 2 +- > net/core/scm.c | 32 +----------------------------- > 5 files changed, 57 insertions(+), 33 deletions(-) > > diff --git a/fs/file.c b/fs/file.c > index abb8b7081d7a..fcfddae0d252 100644 > --- a/fs/file.c > +++ b/fs/file.c > @@ -11,6 +11,7 @@ > #include <linux/export.h> > #include <linux/fs.h> > #include <linux/mm.h> > +#include <linux/net.h> > #include <linux/sched/signal.h> > #include <linux/slab.h> > #include <linux/file.h> > @@ -18,6 +19,8 @@ > #include <linux/bitops.h> > #include <linux/spinlock.h> > #include <linux/rcupdate.h> > +#include <net/cls_cgroup.h> > +#include <net/netprio_cgroup.h> > > unsigned int sysctl_nr_open __read_mostly = 1024*1024; > unsigned int sysctl_nr_open_min = BITS_PER_LONG; > @@ -931,6 +934,50 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) > return err; > } > > +/** > + * __fd_install_received() - Install received file into file descriptor table > + * > + * @fd: fd to install into (if negative, a new fd will be allocated) > + * @file: struct file that was received from another process > + * @ufd_required: true to use @ufd for writing fd number to userspace > + * @ufd: __user pointer to write new fd number to > + * @o_flags: the O_* flags to apply to the new fd entry > + * > + * Installs a received file into the file descriptor table, with appropriate > + * checks and count updates. Optionally writes the fd number to userspace. > + * > + * Returns -ve on error. > + */ > +int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags) > +{ > + struct socket *sock; > + int new_fd; > + int error; > + > + error = security_file_receive(file); > + if (error) > + return error; > + > + new_fd = get_unused_fd_flags(o_flags); > + if (new_fd < 0) > + return new_fd; > + > + error = put_user(new_fd, ufd); > + if (error) { > + put_unused_fd(new_fd); > + return error; > + } > + > + /* Bump the usage count and install the file. */ > + sock = sock_from_file(file, &error); > + if (sock) { > + sock_update_netprioidx(&sock->sk->sk_cgrp_data); > + sock_update_classid(&sock->sk->sk_cgrp_data); > + } > + fd_install(new_fd, get_file(file)); > + return 0; > +} > + > static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) > { > int err = -EBADF; > diff --git a/include/linux/file.h b/include/linux/file.h > index 122f80084a3e..fe18a1a0d555 100644 > --- a/include/linux/file.h > +++ b/include/linux/file.h > @@ -91,6 +91,14 @@ extern void put_unused_fd(unsigned int fd); > > extern void fd_install(unsigned int fd, struct file *file); > > +extern int __fd_install_received(struct file *file, int __user *ufd, > + unsigned int o_flags); > +static inline int fd_install_received_user(struct file *file, int __user *ufd, > + unsigned int o_flags) > +{ > + return __fd_install_received(file, ufd, o_flags); > +} Shouldn't this be the other way around such that fd_install_received_user() is the workhorse that has a "ufd" argument and fd_install_received() is the static inline function that doesn't? extern int fd_install_received_user(struct file *file, int __user *ufd, unsigned int o_flags) static inline int fd_install_received(struct file *file, unsigned int o_flags) { return fd_install_received_user(file, NULL, o_flags); } (So I'm on vacation this week some my reviews are selective and spotty but I promise to be back next week. :)) Christian > + > extern void flush_delayed_fput(void); > extern void __fput_sync(struct file *); > > diff --git a/include/net/scm.h b/include/net/scm.h > index 581a94d6c613..1ce365f4c256 100644 > --- a/include/net/scm.h > +++ b/include/net/scm.h > @@ -37,7 +37,6 @@ struct scm_cookie { > #endif > }; > > -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags); > void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); > void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); > int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); > diff --git a/net/compat.c b/net/compat.c > index 27d477fdcaa0..94f288e8dac5 100644 > --- a/net/compat.c > +++ b/net/compat.c > @@ -298,7 +298,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) > int err = 0, i; > > for (i = 0; i < fdmax; i++) { > - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); > + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); > if (err) > break; > } > diff --git a/net/core/scm.c b/net/core/scm.c > index 6151678c73ed..df190f1fdd28 100644 > --- a/net/core/scm.c > +++ b/net/core/scm.c > @@ -280,36 +280,6 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter > } > EXPORT_SYMBOL(put_cmsg_scm_timestamping); > > -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags) > -{ > - struct socket *sock; > - int new_fd; > - int error; > - > - error = security_file_receive(file); > - if (error) > - return error; > - > - new_fd = get_unused_fd_flags(o_flags); > - if (new_fd < 0) > - return new_fd; > - > - error = put_user(new_fd, ufd); > - if (error) { > - put_unused_fd(new_fd); > - return error; > - } > - > - /* Bump the usage count and install the file. */ > - sock = sock_from_file(file, &error); > - if (sock) { > - sock_update_netprioidx(&sock->sk->sk_cgrp_data); > - sock_update_classid(&sock->sk->sk_cgrp_data); > - } > - fd_install(new_fd, get_file(file)); > - return 0; > -} > - > static int scm_max_fds(struct msghdr *msg) > { > if (msg->msg_controllen <= sizeof(struct cmsghdr)) > @@ -336,7 +306,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) > } > > for (i = 0; i < fdmax; i++) { > - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); > + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); > if (err) > break; > } > -- > 2.25.1 >
On Thu, Jun 18, 2020 at 10:56:14AM +0200, Christian Brauner wrote: > On Mon, Jun 15, 2020 at 08:25:15PM -0700, Kees Cook wrote: > > In preparation for users of the "install a received file" logic outside > > of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from > > net/core/scm.c to __fd_install_received() in fs/file.c, and provide a > > wrapper named fd_install_received_user(), as future patches will change > > the interface to __fd_install_received(). > > > > Signed-off-by: Kees Cook <keescook@chromium.org> > > --- > > fs/file.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/file.h | 8 ++++++++ > > include/net/scm.h | 1 - > > net/compat.c | 2 +- > > net/core/scm.c | 32 +----------------------------- > > 5 files changed, 57 insertions(+), 33 deletions(-) > > > > diff --git a/fs/file.c b/fs/file.c > > index abb8b7081d7a..fcfddae0d252 100644 > > --- a/fs/file.c > > +++ b/fs/file.c > > @@ -11,6 +11,7 @@ > > #include <linux/export.h> > > #include <linux/fs.h> > > #include <linux/mm.h> > > +#include <linux/net.h> > > #include <linux/sched/signal.h> > > #include <linux/slab.h> > > #include <linux/file.h> > > @@ -18,6 +19,8 @@ > > #include <linux/bitops.h> > > #include <linux/spinlock.h> > > #include <linux/rcupdate.h> > > +#include <net/cls_cgroup.h> > > +#include <net/netprio_cgroup.h> > > > > unsigned int sysctl_nr_open __read_mostly = 1024*1024; > > unsigned int sysctl_nr_open_min = BITS_PER_LONG; > > @@ -931,6 +934,50 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) > > return err; > > } > > > > +/** > > + * __fd_install_received() - Install received file into file descriptor table > > + * > > + * @fd: fd to install into (if negative, a new fd will be allocated) > > + * @file: struct file that was received from another process > > + * @ufd_required: true to use @ufd for writing fd number to userspace > > + * @ufd: __user pointer to write new fd number to > > + * @o_flags: the O_* flags to apply to the new fd entry > > + * > > + * Installs a received file into the file descriptor table, with appropriate > > + * checks and count updates. Optionally writes the fd number to userspace. > > + * > > + * Returns -ve on error. > > + */ > > +int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags) > > +{ > > + struct socket *sock; > > + int new_fd; > > + int error; > > + > > + error = security_file_receive(file); > > + if (error) > > + return error; > > + > > + new_fd = get_unused_fd_flags(o_flags); > > + if (new_fd < 0) > > + return new_fd; > > + > > + error = put_user(new_fd, ufd); > > + if (error) { > > + put_unused_fd(new_fd); > > + return error; > > + } > > + > > + /* Bump the usage count and install the file. */ > > + sock = sock_from_file(file, &error); > > + if (sock) { > > + sock_update_netprioidx(&sock->sk->sk_cgrp_data); > > + sock_update_classid(&sock->sk->sk_cgrp_data); > > + } > > + fd_install(new_fd, get_file(file)); > > + return 0; > > +} > > + > > static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) > > { > > int err = -EBADF; > > diff --git a/include/linux/file.h b/include/linux/file.h > > index 122f80084a3e..fe18a1a0d555 100644 > > --- a/include/linux/file.h > > +++ b/include/linux/file.h > > @@ -91,6 +91,14 @@ extern void put_unused_fd(unsigned int fd); > > > > extern void fd_install(unsigned int fd, struct file *file); > > > > +extern int __fd_install_received(struct file *file, int __user *ufd, > > + unsigned int o_flags); > > +static inline int fd_install_received_user(struct file *file, int __user *ufd, > > + unsigned int o_flags) > > +{ > > + return __fd_install_received(file, ufd, o_flags); > > +} > > Shouldn't this be the other way around such that > fd_install_received_user() is the workhorse that has a "ufd" argument > and fd_install_received() is the static inline function that doesn't? > > extern int fd_install_received_user(struct file *file, int __user *ufd, unsigned int o_flags) > static inline int fd_install_received(struct file *file, unsigned int o_flags) > { > return fd_install_received_user(file, NULL, o_flags); > } So, I think it's all worked out in v5[1], so the helper argument handling is better for the ufd case, as David pointed out earlier. (As in, I think you're reacting to the same general problem here.) > (So I'm on vacation this week some my reviews are selective and spotty > but I promise to be back next week. :)) No worries! -Kees [1] https://lore.kernel.org/lkml/20200617220327.3731559-1-keescook@chromium.org/
diff --git a/fs/file.c b/fs/file.c index abb8b7081d7a..fcfddae0d252 100644 --- a/fs/file.c +++ b/fs/file.c @@ -11,6 +11,7 @@ #include <linux/export.h> #include <linux/fs.h> #include <linux/mm.h> +#include <linux/net.h> #include <linux/sched/signal.h> #include <linux/slab.h> #include <linux/file.h> @@ -18,6 +19,8 @@ #include <linux/bitops.h> #include <linux/spinlock.h> #include <linux/rcupdate.h> +#include <net/cls_cgroup.h> +#include <net/netprio_cgroup.h> unsigned int sysctl_nr_open __read_mostly = 1024*1024; unsigned int sysctl_nr_open_min = BITS_PER_LONG; @@ -931,6 +934,50 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) return err; } +/** + * __fd_install_received() - Install received file into file descriptor table + * + * @fd: fd to install into (if negative, a new fd will be allocated) + * @file: struct file that was received from another process + * @ufd_required: true to use @ufd for writing fd number to userspace + * @ufd: __user pointer to write new fd number to + * @o_flags: the O_* flags to apply to the new fd entry + * + * Installs a received file into the file descriptor table, with appropriate + * checks and count updates. Optionally writes the fd number to userspace. + * + * Returns -ve on error. + */ +int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags) +{ + struct socket *sock; + int new_fd; + int error; + + error = security_file_receive(file); + if (error) + return error; + + new_fd = get_unused_fd_flags(o_flags); + if (new_fd < 0) + return new_fd; + + error = put_user(new_fd, ufd); + if (error) { + put_unused_fd(new_fd); + return error; + } + + /* Bump the usage count and install the file. */ + sock = sock_from_file(file, &error); + if (sock) { + sock_update_netprioidx(&sock->sk->sk_cgrp_data); + sock_update_classid(&sock->sk->sk_cgrp_data); + } + fd_install(new_fd, get_file(file)); + return 0; +} + static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) { int err = -EBADF; diff --git a/include/linux/file.h b/include/linux/file.h index 122f80084a3e..fe18a1a0d555 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -91,6 +91,14 @@ extern void put_unused_fd(unsigned int fd); extern void fd_install(unsigned int fd, struct file *file); +extern int __fd_install_received(struct file *file, int __user *ufd, + unsigned int o_flags); +static inline int fd_install_received_user(struct file *file, int __user *ufd, + unsigned int o_flags) +{ + return __fd_install_received(file, ufd, o_flags); +} + extern void flush_delayed_fput(void); extern void __fput_sync(struct file *); diff --git a/include/net/scm.h b/include/net/scm.h index 581a94d6c613..1ce365f4c256 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -37,7 +37,6 @@ struct scm_cookie { #endif }; -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags); void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); diff --git a/net/compat.c b/net/compat.c index 27d477fdcaa0..94f288e8dac5 100644 --- a/net/compat.c +++ b/net/compat.c @@ -298,7 +298,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) int err = 0, i; for (i = 0; i < fdmax; i++) { - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); if (err) break; } diff --git a/net/core/scm.c b/net/core/scm.c index 6151678c73ed..df190f1fdd28 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -280,36 +280,6 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter } EXPORT_SYMBOL(put_cmsg_scm_timestamping); -int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags) -{ - struct socket *sock; - int new_fd; - int error; - - error = security_file_receive(file); - if (error) - return error; - - new_fd = get_unused_fd_flags(o_flags); - if (new_fd < 0) - return new_fd; - - error = put_user(new_fd, ufd); - if (error) { - put_unused_fd(new_fd); - return error; - } - - /* Bump the usage count and install the file. */ - sock = sock_from_file(file, &error); - if (sock) { - sock_update_netprioidx(&sock->sk->sk_cgrp_data); - sock_update_classid(&sock->sk->sk_cgrp_data); - } - fd_install(new_fd, get_file(file)); - return 0; -} - static int scm_max_fds(struct msghdr *msg) { if (msg->msg_controllen <= sizeof(struct cmsghdr)) @@ -336,7 +306,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) } for (i = 0; i < fdmax; i++) { - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); + err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); if (err) break; }
In preparation for users of the "install a received file" logic outside of net/ (pidfd and seccomp), relocate and rename __scm_install_fd() from net/core/scm.c to __fd_install_received() in fs/file.c, and provide a wrapper named fd_install_received_user(), as future patches will change the interface to __fd_install_received(). Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/file.c | 47 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/file.h | 8 ++++++++ include/net/scm.h | 1 - net/compat.c | 2 +- net/core/scm.c | 32 +----------------------------- 5 files changed, 57 insertions(+), 33 deletions(-)