linux-stable.git/include/linux, branch v3.16.52 Linux kernel stable tree ptrace: Properly initialize ptracer_cred on fork 2018-01-01T20:52:11+00:00 Eric W. Biederman ebiederm@xmission.com 2017-05-22T20:40:12+00:00 7dd8d19f44c65eb1567685ab8b0fe06d7cb584fc commit c70d9d809fdeecedb96972457ee45c49a232d97f upstream. When I introduced ptracer_cred I failed to consider the weirdness of fork where the task_struct copies the old value by default. This winds up leaving ptracer_cred set even when a process forks and the child process does not wind up being ptraced. Because ptracer_cred is not set on non-ptraced processes whose parents were ptraced this has broken the ability of the enlightenment window manager to start setuid children. Fix this by properly initializing ptracer_cred in ptrace_init_task This must be done with a little bit of care to preserve the current value of ptracer_cred when ptrace carries through fork. Re-reading the ptracer_cred from the ptracing process at this point is inconsistent with how PT_PTRACE_CAP has been maintained all of these years. Tested-by: Takashi Iwai <tiwai@suse.de> Fixes: 64b875f7ac8a ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c70d9d809fdeecedb96972457ee45c49a232d97f upstream.

When I introduced ptracer_cred I failed to consider the weirdness of
fork where the task_struct copies the old value by default.  This
winds up leaving ptracer_cred set even when a process forks and
the child process does not wind up being ptraced.

Because ptracer_cred is not set on non-ptraced processes whose
parents were ptraced this has broken the ability of the enlightenment
window manager to start setuid children.

Fix this by properly initializing ptracer_cred in ptrace_init_task

This must be done with a little bit of care to preserve the current value
of ptracer_cred when ptrace carries through fork.  Re-reading the
ptracer_cred from the ptracing process at this point is inconsistent
with how PT_PTRACE_CAP has been maintained all of these years.

Tested-by: Takashi Iwai <tiwai@suse.de>
Fixes: 64b875f7ac8a ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ptrace: Don't allow accessing an undumpable mm 2018-01-01T20:52:11+00:00 Eric W. Biederman ebiederm@xmission.com 2016-11-22T18:06:50+00:00 aa3fbddbb80119b4cffbb45581c8542d9dcdec79 commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 upstream. It is the reasonable expectation that if an executable file is not readable there will be no way for a user without special privileges to read the file. This is enforced in ptrace_attach but if ptrace is already attached before exec there is no enforcement for read-only executables. As the only way to read such an mm is through access_process_vm spin a variant called ptrace_access_vm that will fail if the target process is not being ptraced by the current process, or the current process did not have sufficient privileges when ptracing began to read the target processes mm. In the ptrace implementations replace access_process_vm by ptrace_access_vm. There remain several ptrace sites that still use access_process_vm as they are reading the target executables instructions (for kernel consumption) or register stacks. As such it does not appear necessary to add a permission check to those calls. This bug has always existed in Linux. Fixes: v1.0 Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [bwh: Backported to 3.16: - Pass around only a write flag, not gup_flags - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 upstream.

It is the reasonable expectation that if an executable file is not
readable there will be no way for a user without special privileges to
read the file.  This is enforced in ptrace_attach but if ptrace
is already attached before exec there is no enforcement for read-only
executables.

As the only way to read such an mm is through access_process_vm
spin a variant called ptrace_access_vm that will fail if the
target process is not being ptraced by the current process, or
the current process did not have sufficient privileges when ptracing
began to read the target processes mm.

In the ptrace implementations replace access_process_vm by
ptrace_access_vm.  There remain several ptrace sites that still use
access_process_vm as they are reading the target executables
instructions (for kernel consumption) or register stacks.  As such it
does not appear necessary to add a permission check to those calls.

This bug has always existed in Linux.

Fixes: v1.0
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.16:
 - Pass around only a write flag, not gup_flags
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
exec: Ensure mm->user_ns contains the execed files 2018-01-01T20:52:11+00:00 Eric W. Biederman ebiederm@xmission.com 2016-11-17T04:06:51+00:00 a0d8337f16fb5d5dd7b963f092779bc990a1cc0e commit f84df2a6f268de584a201e8911384a2d244876e3 upstream. When the user namespace support was merged the need to prevent ptrace from revealing the contents of an unreadable executable was overlooked. Correct this oversight by ensuring that the executed file or files are in mm->user_ns, by adjusting mm->user_ns. Use the new function privileged_wrt_inode_uidgid to see if the executable is a member of the user namespace, and as such if having CAP_SYS_PTRACE in the user namespace should allow tracing the executable. If not update mm->user_ns to the parent user namespace until an appropriate parent is found. Reported-by: Jann Horn <jann@thejh.net> Fixes: 9e4a36ece652 ("userns: Fail exec for suid and sgid binaries with ids outside our user namespace.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [bwh: Backported to 3.16: - Add #include <linux/user_namespace.h> - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f84df2a6f268de584a201e8911384a2d244876e3 upstream.

When the user namespace support was merged the need to prevent
ptrace from revealing the contents of an unreadable executable
was overlooked.

Correct this oversight by ensuring that the executed file
or files are in mm->user_ns, by adjusting mm->user_ns.

Use the new function privileged_wrt_inode_uidgid to see if
the executable is a member of the user namespace, and as such
if having CAP_SYS_PTRACE in the user namespace should allow
tracing the executable.  If not update mm->user_ns to
the parent user namespace until an appropriate parent is found.

Reported-by: Jann Horn <jann@thejh.net>
Fixes: 9e4a36ece652 ("userns: Fail exec for suid and sgid binaries with ids outside our user namespace.")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.16:
 - Add #include <linux/user_namespace.h>
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ptrace: Capture the ptracer's creds not PT_PTRACE_CAP 2018-01-01T20:52:10+00:00 Eric W. Biederman ebiederm@xmission.com 2016-11-15T00:48:07+00:00 d55a94ed03a24794d47f80d5300825f6c095a0a7 commit 64b875f7ac8a5d60a4e191479299e931ee949b67 upstream. When the flag PT_PTRACE_CAP was added the PTRACE_TRACEME path was overlooked. This can result in incorrect behavior when an application like strace traces an exec of a setuid executable. Further PT_PTRACE_CAP does not have enough information for making good security decisions as it does not report which user namespace the capability is in. This has already allowed one mistake through insufficient granulariy. I found this issue when I was testing another corner case of exec and discovered that I could not get strace to set PT_PTRACE_CAP even when running strace as root with a full set of caps. This change fixes the above issue with strace allowing stracing as root a setuid executable without disabling setuid. More fundamentaly this change allows what is allowable at all times, by using the correct information in it's decision. Fixes: 4214e42f96d4 ("v2.4.9.11 -> v2.4.9.12") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 64b875f7ac8a5d60a4e191479299e931ee949b67 upstream.

When the flag PT_PTRACE_CAP was added the PTRACE_TRACEME path was
overlooked.  This can result in incorrect behavior when an application
like strace traces an exec of a setuid executable.

Further PT_PTRACE_CAP does not have enough information for making good
security decisions as it does not report which user namespace the
capability is in.  This has already allowed one mistake through
insufficient granulariy.

I found this issue when I was testing another corner case of exec and
discovered that I could not get strace to set PT_PTRACE_CAP even when
running strace as root with a full set of caps.

This change fixes the above issue with strace allowing stracing as
root a setuid executable without disabling setuid.  More fundamentaly
this change allows what is allowable at all times, by using the correct
information in it's decision.

Fixes: 4214e42f96d4 ("v2.4.9.11 -> v2.4.9.12")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm: Add a user_ns owner to mm_struct and fix ptrace permission checks 2018-01-01T20:52:10+00:00 Eric W. Biederman ebiederm@xmission.com 2016-10-14T02:23:16+00:00 d5b3e840dbf6dd2c0f30b5982b6f5ecd49e46b12 commit bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 upstream. During exec dumpable is cleared if the file that is being executed is not readable by the user executing the file. A bug in ptrace_may_access allows reading the file if the executable happens to enter into a subordinate user namespace (aka clone(CLONE_NEWUSER), unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER). This problem is fixed with only necessary userspace breakage by adding a user namespace owner to mm_struct, captured at the time of exec, so it is clear in which user namespace CAP_SYS_PTRACE must be present in to be able to safely give read permission to the executable. The function ptrace_may_access is modified to verify that the ptracer has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns. This ensures that if the task changes it's cred into a subordinate user namespace it does not become ptraceable. The function ptrace_attach is modified to only set PT_PTRACE_CAP when CAP_SYS_PTRACE is held over task->mm->user_ns. The intent of PT_PTRACE_CAP is to be a flag to note that whatever permission changes the task might go through the tracer has sufficient permissions for it not to be an issue. task->cred->user_ns is always the same as or descendent of mm->user_ns. Which guarantees that having CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks credentials. To prevent regressions mm->dumpable and mm->user_ns are not considered when a task has no mm. As simply failing ptrace_may_attach causes regressions in privileged applications attempting to read things such as /proc/<pid>/stat Acked-by: Kees Cook <keescook@chromium.org> Tested-by: Cyrill Gorcunov <gorcunov@openvz.org> Fixes: 8409cca70561 ("userns: allow ptrace from non-init user namespaces") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 upstream.

During exec dumpable is cleared if the file that is being executed is
not readable by the user executing the file.  A bug in
ptrace_may_access allows reading the file if the executable happens to
enter into a subordinate user namespace (aka clone(CLONE_NEWUSER),
unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER).

This problem is fixed with only necessary userspace breakage by adding
a user namespace owner to mm_struct, captured at the time of exec, so
it is clear in which user namespace CAP_SYS_PTRACE must be present in
to be able to safely give read permission to the executable.

The function ptrace_may_access is modified to verify that the ptracer
has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns.
This ensures that if the task changes it's cred into a subordinate
user namespace it does not become ptraceable.

The function ptrace_attach is modified to only set PT_PTRACE_CAP when
CAP_SYS_PTRACE is held over task->mm->user_ns.  The intent of
PT_PTRACE_CAP is to be a flag to note that whatever permission changes
the task might go through the tracer has sufficient permissions for
it not to be an issue.  task->cred->user_ns is always the same
as or descendent of mm->user_ns.  Which guarantees that having
CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks
credentials.

To prevent regressions mm->dumpable and mm->user_ns are not considered
when a task has no mm.  As simply failing ptrace_may_attach causes
regressions in privileged applications attempting to read things
such as /proc/<pid>/stat

Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Fixes: 8409cca70561 ("userns: allow ptrace from non-init user namespaces")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter/ipvs: clear ipvs_property flag when SKB net namespace changed 2018-01-01T20:52:04+00:00 Ye Yin hustcat@gmail.com 2017-10-26T08:57:05+00:00 81ecd600d8dbb8799faa6d9d680790c6e4827019 commit 2b5ec1a5f9738ee7bf8f5ec0526e75e00362c48f upstream. When run ipvs in two different network namespace at the same host, and one ipvs transport network traffic to the other network namespace ipvs. 'ipvs_property' flag will make the second ipvs take no effect. So we should clear 'ipvs_property' when SKB network namespace changed. Fixes: 621e84d6f373 ("dev: introduce skb_scrub_packet()") Signed-off-by: Ye Yin <hustcat@gmail.com> Signed-off-by: Wei Zhou <chouryzhou@gmail.com> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2b5ec1a5f9738ee7bf8f5ec0526e75e00362c48f upstream.

When run ipvs in two different network namespace at the same host, and one
ipvs transport network traffic to the other network namespace ipvs.
'ipvs_property' flag will make the second ipvs take no effect. So we should
clear 'ipvs_property' when SKB network namespace changed.

Fixes: 621e84d6f373 ("dev: introduce skb_scrub_packet()")
Signed-off-by: Ye Yin <hustcat@gmail.com>
Signed-off-by: Wei Zhou <chouryzhou@gmail.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86/uaccess, sched/preempt: Verify access_ok() context 2018-01-01T20:52:01+00:00 Peter Zijlstra peterz@infradead.org 2016-11-22T09:57:15+00:00 65143814913b0e87e3acae21ef12cffc44bc13ae commit 7c4788950ba5922fde976d80b72baf46f14dee8d upstream. I recently encountered wreckage because access_ok() was used where it should not be, add an explicit WARN when access_ok() is used wrongly. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.16: - Adjust filename - Include <linux/preempt_mask.h> in <asm/uaccess.h> since it's not included by <linux/uaccess.h>] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 7c4788950ba5922fde976d80b72baf46f14dee8d upstream.

I recently encountered wreckage because access_ok() was used where it
should not be, add an explicit WARN when access_ok() is used wrongly.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
 - Adjust filename
 - Include <linux/preempt_mask.h> in <asm/uaccess.h> since it's not included by
   <linux/uaccess.h>]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
pci_ids: Add PCI device IDs for F15h M60h 2018-01-01T20:51:57+00:00 Aravind Gopalakrishnan Aravind.Gopalakrishnan@amd.com 2014-09-18T19:56:35+00:00 ee044ffb906f4be8502b3a721e8aa6282cffbe8b commit 4cbbdb51cc921f95978360fd7a0652d493dadc3e upstream. Add F3, F4 device IDs to be used in amd_nb.c and amd64_edac.c Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/1411070195-10177-1-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 4cbbdb51cc921f95978360fd7a0652d493dadc3e upstream.

Add F3, F4 device IDs to be used in amd_nb.c and amd64_edac.c

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1411070195-10177-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tun: call dev_get_valid_name() before register_netdevice() 2018-01-01T20:51:54+00:00 Cong Wang xiyou.wangcong@gmail.com 2017-10-13T18:58:53+00:00 ff31768dd6814abefb7724fa6dc0976b33edce0e commit 0ad646c81b2182f7fa67ec0c8c825e0ee165696d upstream. register_netdevice() could fail early when we have an invalid dev name, in which case ->ndo_uninit() is not called. For tun device, this is a problem because a timer etc. are already initialized and it expects ->ndo_uninit() to clean them up. We could move these initializations into a ->ndo_init() so that register_netdevice() knows better, however this is still complicated due to the logic in tun_detach(). Therefore, I choose to just call dev_get_valid_name() before register_netdevice(), which is quicker and much easier to audit. And for this specific case, it is already enough. Fixes: 96442e42429e ("tuntap: choose the txq based on rxq") Reported-by: Dmitry Alexeev <avekceeb@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 0ad646c81b2182f7fa67ec0c8c825e0ee165696d upstream.

register_netdevice() could fail early when we have an invalid
dev name, in which case ->ndo_uninit() is not called. For tun
device, this is a problem because a timer etc. are already
initialized and it expects ->ndo_uninit() to clean them up.

We could move these initializations into a ->ndo_init() so
that register_netdevice() knows better, however this is still
complicated due to the logic in tun_detach().

Therefore, I choose to just call dev_get_valid_name() before
register_netdevice(), which is quicker and much easier to audit.
And for this specific case, it is already enough.

Fixes: 96442e42429e ("tuntap: choose the txq based on rxq")
Reported-by: Dmitry Alexeev <avekceeb@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fs/mpage.c: fix mpage_writepage() for pages with buffers 2018-01-01T20:51:53+00:00 Matthew Wilcox willy@infradead.org 2017-10-13T22:58:15+00:00 ef0dd635486e4c342f5d7fc64b91b5e4563a960a commit f892760aa66a2d657deaf59538fb69433036767c upstream. When using FAT on a block device which supports rw_page, we can hit BUG_ON(!PageLocked(page)) in try_to_free_buffers(). This is because we call clean_buffers() after unlocking the page we've written. Introduce a new clean_page_buffers() which cleans all buffers associated with a page and call it from within bdev_write_page(). [akpm@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew] Link: http://lkml.kernel.org/r/20171006211541.GA7409@bombadil.infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Tested-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f892760aa66a2d657deaf59538fb69433036767c upstream.

When using FAT on a block device which supports rw_page, we can hit
BUG_ON(!PageLocked(page)) in try_to_free_buffers().  This is because we
call clean_buffers() after unlocking the page we've written.  Introduce
a new clean_page_buffers() which cleans all buffers associated with a
page and call it from within bdev_write_page().

[akpm@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew]
Link: http://lkml.kernel.org/r/20171006211541.GA7409@bombadil.infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>