commit ef1548adada51a2f32ed7faef50aa465e1b4c5da upstream.
Recently syzbot reported that unmounting proc when there is an ongoing
inotify watch on the root directory of proc could result in a use
after free when the watch is removed after the unmount of proc
when the watcher exits.
Commit 69879c01a0c3 ("proc: Remove the now unnecessary internal mount
of proc") made it easier to unmount proc and allowed syzbot to see the
problem, but looking at the code it has been around for a long time.
Looking at the code the fsnotify watch should have been removed by
fsnotify_sb_delete in generic_shutdown_super. Unfortunately the inode
was allocated with new_inode_pseudo instead of new_inode so the inode
was not on the sb->s_inodes list. Which prevented
fsnotify_unmount_inodes from finding the inode and removing the watch
as well as made it so the "VFS: Busy inodes after unmount" warning
could not find the inodes to warn about them.
Make all of the inodes in proc visible to generic_shutdown_super,
and fsnotify_sb_delete by using new_inode instead of new_inode_pseudo.
The only functional difference is that new_inode places the inodes
on the sb->s_inodes list.
I wrote a small test program and I can verify that without changes it
can trigger this issue, and by replacing new_inode_pseudo with
new_inode the issues goes away.
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/000000000000d788c905a7dfa3f4@google.com
Reported-by: syzbot+7d2debdcdb3cb93c1e5e@syzkaller.appspotmail.com
Fixes: 0097875bd415 ("proc: Implement /proc/thread-self to point at the directory of the current thread")
Fixes: 021ada7dff22 ("procfs: switch /proc/self away from proc_dir_entry")
Fixes: 51f0885e5415 ("vfs,proc: guarantee unique inodes in /proc")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bdebd6a2831b6fab69eb85cee74a8ba77f1a1cc2 upstream.
remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:
- not detecting pgoff<<PAGE_SHIFT overflow
- not detecting (pgoff<<PAGE_SHIFT)+usize overflow
- not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same
vmalloc allocation
- comparing a potentially wildly out-of-bounds pointer with the end of
the vmalloc region
In particular, since commit fc9702273e2e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.
This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.
To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff<<PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().
In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.
Fixes: 833423143c3a ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 94d440d618467806009c8edc70b094d64e12ee5a upstream.
Michael Kerrisk suggested to replace numeric clock IDs with symbolic names.
Now the content of these files looks like this:
$ cat /proc/774/timens_offsets
monotonic 864000 0
boottime 1728000 0
For setting offsets, both representations of clocks (numeric and symbolic)
can be used.
As for compatibility, it is acceptable to change things as long as
userspace doesn't care. The format of timens_offsets files is very new and
there are no userspace tools yet which rely on this format.
But three projects crun, util-linux and criu rely on the interface of
setting time offsets and this is why it's required to continue supporting
the numeric clock IDs on write.
Fixes: 04a8682a71be ("fs/proc: Introduce /proc/pid/timens_offsets")
Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200411154031.642557-1-avagin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull vfs file system parameter updates from Al Viro: "Saner fs_parser.c guts and data structures. The system-wide registry of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is the horror switch() in fs_parse() that would have to grow another case every time something got added to that system-wide registry. New syntax types can be added by filesystems easily now, and their namespace is that of functions - not of system-wide enum members. IOW, they can be shared or kept private and if some turn out to be widely useful, we can make them common library helpers, etc., without having to do anything whatsoever to fs_parse() itself. And we already get that kind of requests - the thing that finally pushed me into doing that was "oh, and let's add one for timeouts - things like 15s or 2h". If some filesystem really wants that, let them do it. Without somebody having to play gatekeeper for the variants blessed by direct support in fs_parse(), TYVM. Quite a bit of boilerplate is gone. And IMO the data structures make a lot more sense now. -200LoC, while we are at it" * 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits) tmpfs: switch to use of invalfc() cgroup1: switch to use of errorfc() et.al. procfs: switch to use of invalfc() hugetlbfs: switch to use of invalfc() cramfs: switch to use of errofc() et.al. gfs2: switch to use of errorfc() et.al. fuse: switch to use errorfc() et.al. ceph: use errorfc() and friends instead of spelling the prefix out prefix-handling analogues of errorf() and friends turn fs_param_is_... into functions fs_parse: handle optional arguments sanely fs_parse: fold fs_parameter_desc/fs_parameter_spec fs_parser: remove fs_parameter_description name field add prefix to fs_context->log ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log new primitive: __fs_parse() switch rbd and libceph to p_log-based primitives struct p_log, variants of warnf() et.al. taking that one instead teach logfc() to handle prefices, give it saner calling conventions get rid of cg_invalf() ...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The former contains nothing but a pointer to an array of the latter... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Unused now. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull tracing updates from Steven Rostedt: - Added new "bootconfig". This looks for a file appended to initrd to add boot config options, and has been discussed thoroughly at Linux Plumbers. Very useful for adding kprobes at bootup. Only enabled if "bootconfig" is on the real kernel command line. - Created dynamic event creation. Merges common code between creating synthetic events and kprobe events. - Rename perf "ring_buffer" structure to "perf_buffer" - Rename ftrace "ring_buffer" structure to "trace_buffer" Had to rename existing "trace_buffer" to "array_buffer" - Allow trace_printk() to work withing (some) tracing code. - Sort of tracing configs to be a little better organized - Fixed bug where ftrace_graph hash was not being protected properly - Various other small fixes and clean ups * tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits) bootconfig: Show the number of nodes on boot message tools/bootconfig: Show the number of bootconfig nodes bootconfig: Add more parse error messages bootconfig: Use bootconfig instead of boot config ftrace: Protect ftrace_graph_hash with ftrace_sync ftrace: Add comment to why rcu_dereference_sched() is open coded tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu tracing: Annotate ftrace_graph_hash pointer with __rcu bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline tracing: Use seq_buf for building dynevent_cmd string tracing: Remove useless code in dynevent_arg_pair_add() tracing: Remove check_arg() callbacks from dynevent args tracing: Consolidate some synth_event_trace code tracing: Fix now invalid var_ref_vals assumption in trace action tracing: Change trace_boot to use synth_event interface tracing: Move tracing selftests to bottom of menu tracing: Move mmio tracer config up with the other tracers tracing: Move tracing test module configs together tracing: Move all function tracing configs together tracing: Documentation for in-kernel synthetic event API ...
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently core /proc code uses "struct file_operations" for custom hooks, however, VFS doesn't directly call them. Every time VFS expands file_operations hook set, /proc code bloats for no reason. Introduce "struct proc_ops" which contains only those hooks which /proc allows to call into (open, release, read, write, ioctl, mmap, poll). It doesn't contain module pointer as well. Save ~184 bytes per usage: add/remove: 26/26 grow/shrink: 1/4 up/down: 1922/-6674 (-4752) Function old new delta sysvipc_proc_ops - 72 +72 ... config_gz_proc_ops - 72 +72 proc_get_inode 289 339 +50 proc_reg_get_unmapped_area 110 107 -3 close_pdeo 227 224 -3 proc_reg_open 289 284 -5 proc_create_data 60 53 -7 rt_cpu_seq_fops 256 - -256 ... default_affinity_proc_fops 256 - -256 Total: Before=5430095, After=5425343, chg -0.09% Link: http://lkml.kernel.org/r/20191225172228.GA13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>