commit f612acfae86af7ecad754ae6a46019be9da05b8e upstream.
syzkaller report this:
BUG: memory leak
unreferenced object 0xffffc9000488d000 (size 9195520):
comm "syz-executor.0", pid 2752, jiffies 4294787496 (age 18.757s)
hex dump (first 32 bytes):
ff ff ff ff ff ff ff ff a8 00 00 00 01 00 00 00 ................
02 00 00 00 00 00 00 00 80 a1 7a c1 ff ff ff ff ..........z.....
backtrace:
[<000000000863775c>] __vmalloc_node mm/vmalloc.c:1795 [inline]
[<000000000863775c>] __vmalloc_node_flags mm/vmalloc.c:1809 [inline]
[<000000000863775c>] vmalloc+0x8c/0xb0 mm/vmalloc.c:1831
[<000000003f668111>] kernel_read_file+0x58f/0x7d0 fs/exec.c:924
[<000000002385813f>] kernel_read_file_from_fd+0x49/0x80 fs/exec.c:993
[<0000000011953ff1>] __do_sys_finit_module+0x13b/0x2a0 kernel/module.c:3895
[<000000006f58491f>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
[<00000000ee78baf4>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<00000000241f889b>] 0xffffffffffffffff
It should goto 'out_free' lable to free allocated buf while kernel_read
fails.
Fixes: 39d637af5aa7 ("vfs: forbid write access when reading a file into memory")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thibaut Sautereau <thibaut@sautereau.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull trivial vfs updates from Al Viro: "A few cleanups + Neil's namespace_unlock() optimization" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: exec: make prepare_bprm_creds static genheaders: %-<width>s had been there since v6; %-*s - since v7 VFS: use synchronize_rcu_expedited() in namespace_unlock() iov_iter: reduce code duplication
This is already done for us internally by the signal machinery. [akpm@linux-foundation.org: fix fs/buffer.c] Link: http://lkml.kernel.org/r/20181116002713.8474-7-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the "extra" size for argv/envp pointers every time, this is a bit ugly and even not strictly correct: acct_arg_size() must not account this size. Remove all the rlimit code in get_arg_page(). Instead, add bprm->argmin calculated once at the start of __do_execve_file() and change copy_strings to check bprm->p >= bprm->argmin. The patch adds the new helper, prepare_arg_pages() which initializes bprm->argc/envc and bprm->argmin. [oleg@redhat.com: fix !CONFIG_MMU version of get_arg_page()] Link: http://lkml.kernel.org/r/20181126122307.GA1660@redhat.com [akpm@linux-foundation.org: use max_t] Link: http://lkml.kernel.org/r/20181112160910.GA28440@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
prepare_bprm_creds is not used outside exec.c, so there's no reason for it to have external linkage. Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Revert commit c22397888f1e "exec: make de_thread() freezable" as
requested by Ingo Molnar:
"So there's a new regression in v4.20-rc4, my desktop produces this
lockdep splat:
[ 1772.588771] WARNING: pkexec/4633 still has locks held!
[ 1772.588773] 4.20.0-rc4-custom-00213-g93a49841322b #1 Not tainted
[ 1772.588775] ------------------------------------
[ 1772.588776] 1 lock held by pkexec/4633:
[ 1772.588778] #0: 00000000ed85fbf8 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x2a/0x70
[ 1772.588786] stack backtrace:
[ 1772.588789] CPU: 7 PID: 4633 Comm: pkexec Not tainted 4.20.0-rc4-custom-00213-g93a49841322b #1
[ 1772.588792] Call Trace:
[ 1772.588800] dump_stack+0x85/0xcb
[ 1772.588803] flush_old_exec+0x116/0x890
[ 1772.588807] ? load_elf_phdrs+0x72/0xb0
[ 1772.588809] load_elf_binary+0x291/0x1620
[ 1772.588815] ? sched_clock+0x5/0x10
[ 1772.588817] ? search_binary_handler+0x6d/0x240
[ 1772.588820] search_binary_handler+0x80/0x240
[ 1772.588823] load_script+0x201/0x220
[ 1772.588825] search_binary_handler+0x80/0x240
[ 1772.588828] __do_execve_file.isra.32+0x7d2/0xa60
[ 1772.588832] ? strncpy_from_user+0x40/0x180
[ 1772.588835] __x64_sys_execve+0x34/0x40
[ 1772.588838] do_syscall_64+0x60/0x1c0
The warning gets triggered by an ancient lockdep check in the freezer:
(gdb) list *0xffffffff812ece06
0xffffffff812ece06 is in flush_old_exec (./include/linux/freezer.h:57).
52 * DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION
53 * If try_to_freeze causes a lockdep warning it means the caller may deadlock
54 */
55 static inline bool try_to_freeze_unsafe(void)
56 {
57 might_sleep();
58 if (likely(!freezing(current)))
59 return false;
60 return __refrigerator(false);
61 }
I reviewed the ->cred_guard_mutex code, and the mutex is held across all
of exec() - and we always did this.
But there's this recent -rc4 commit:
> Chanho Min (1):
> exec: make de_thread() freezable
c22397888f1e: exec: make de_thread() freezable
I believe this commit is bogus, you cannot call try_to_freeze() from
de_thread(), because it's holding the ->cred_guard_mutex."
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Suspend fails due to the exec family of functions blocking the freezer. The casue is that de_thread() sleeps in TASK_UNINTERRUPTIBLE waiting for all sub-threads to die, and we have the deadlock if one of them is frozen. This also can occur with the schedule() waiting for the group thread leader to exit if it is frozen. In our machine, it causes freeze timeout as bellows. Freezing of tasks failed after 20.010 seconds (1 tasks refusing to freeze, wq_busy=0): setcpushares-ls D ffffffc00008ed70 0 5817 1483 0x0040000d Call trace: [<ffffffc00008ed70>] __switch_to+0x88/0xa0 [<ffffffc000d1c30c>] __schedule+0x1bc/0x720 [<ffffffc000d1ca90>] schedule+0x40/0xa8 [<ffffffc0001cd784>] flush_old_exec+0xdc/0x640 [<ffffffc000220360>] load_elf_binary+0x2a8/0x1090 [<ffffffc0001ccff4>] search_binary_handler+0x9c/0x240 [<ffffffc00021c584>] load_script+0x20c/0x228 [<ffffffc0001ccff4>] search_binary_handler+0x9c/0x240 [<ffffffc0001ce8e0>] do_execveat_common.isra.14+0x4f8/0x6e8 [<ffffffc0001cedd0>] compat_SyS_execve+0x38/0x48 [<ffffffc00008de30>] el0_svc_naked+0x24/0x28 To fix this, make de_thread() freezable. It looks safe and works fine. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Chanho Min <chanho.min@lge.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
On 32-bit systems, the buffer allocated by kernel_read_file() is too small if the file size is > SIZE_MAX, due to truncation to size_t. Fortunately, since the 'count' argument to kernel_read() is also truncated to size_t, only the allocated space is filled; then, -EIO is returned since 'pos != i_size' after the read loop. But this is not obvious and seems incidental. We should be more explicit about this case. So, fail early if i_size > SIZE_MAX. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull core signal handling updates from Eric Biederman:
"It was observed that a periodic timer in combination with a
sufficiently expensive fork could prevent fork from every completing.
This contains the changes to remove the need for that restart.
This set of changes is split into several parts:
- The first part makes PIDTYPE_TGID a proper pid type instead
something only for very special cases. The part starts using
PIDTYPE_TGID enough so that in __send_signal where signals are
actually delivered we know if the signal is being sent to a a group
of processes or just a single process.
- With that prep work out of the way the logic in fork is modified so
that fork logically makes signals received while it is running
appear to be received after the fork completes"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
signal: Don't send signals to tasks that don't exist
signal: Don't restart fork when signals come in.
fork: Have new threads join on-going signal group stops
fork: Skip setting TIF_SIGPENDING in ptrace_init_task
signal: Add calculate_sigpending()
fork: Unconditionally exit if a fatal signal is pending
fork: Move and describe why the code examines PIDNS_ADDING
signal: Push pid type down into complete_signal.
signal: Push pid type down into __send_signal
signal: Push pid type down into send_signal
signal: Pass pid type into do_send_sig_info
signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
signal: Pass pid type into group_send_sig_info
signal: Pass pid and pid type into send_sigqueue
posix-timers: Noralize good_sigevent
signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
pid: Implement PIDTYPE_TGID
pids: Move the pgrp and session pid pointers from task_struct to signal_struct
kvm: Don't open code task_pid in kvm_vcpu_ioctl
pids: Compute task_tgid using signal->leader_pid
...
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA. This is unreliable as ->mmap may not set ->vm_ops.
False-positive vma_is_anonymous() may lead to crashes:
next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
------------[ cut here ]------------
kernel BUG at mm/memory.c:1422!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
Call Trace:
unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
unmap_mapping_range_vma mm/memory.c:2792 [inline]
unmap_mapping_range_tree mm/memory.c:2813 [inline]
unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
unmap_mapping_range+0x48/0x60 mm/memory.c:2880
truncate_pagecache+0x54/0x90 mm/truncate.c:800
truncate_setsize+0x70/0xb0 mm/truncate.c:826
simple_setattr+0xe9/0x110 fs/libfs.c:409
notify_change+0xf13/0x10f0 fs/attr.c:335
do_truncate+0x1ac/0x2b0 fs/open.c:63
do_sys_ftruncate+0x492/0x560 fs/open.c:205
__do_sys_ftruncate fs/open.c:215 [inline]
__se_sys_ftruncate fs/open.c:213 [inline]
__x64_sys_ftruncate+0x59/0x80 fs/open.c:213
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reproducer:
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#define KCOV_INIT_TRACE _IOR('c', 1, unsigned long)
#define KCOV_ENABLE _IO('c', 100)
#define KCOV_DISABLE _IO('c', 101)
#define COVER_SIZE (1024<<10)
#define KCOV_TRACE_PC 0
#define KCOV_TRACE_CMP 1
int main(int argc, char **argv)
{
int fd;
unsigned long *cover;
system("mount -t debugfs none /sys/kernel/debug");
fd = open("/sys/kernel/debug/kcov", O_RDWR);
ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
munmap(cover, COVER_SIZE * sizeof(unsigned long));
cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
ftruncate(fd, 3UL << 20);
return 0;
}
This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.
If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops. This way we will have non-NULL ->vm_ops for all VMAs.
Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>