commit 55acdd926f6b21a5cdba23da98a48aedf19ac9c3 upstream. Can be reproduced when running dlm_controld (tested on 4.4.x, 4.12.4): # seq 1 100 | xargs -P0 -n1 dlm_tool join # seq 1 100 | xargs -P0 -n1 dlm_tool leave misc_register fails due to duplicate sysfs entry, which causes dlm_device_register to free ls->ls_device.name. In dlm_device_deregister the name was freed again, causing memory corruption. According to the comment in dlm_device_deregister the name should've been set to NULL when registration fails, so this patch does that. sysfs: cannot create duplicate filename '/dev/char/10:1' ------------[ cut here ]------------ warning: cpu: 1 pid: 4450 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x56/0x70 modules linked in: msr rfcomm dlm ccm bnep dm_crypt uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev btusb media btrtl btbcm btintel bluetooth ecdh_generic intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel thinkpad_acpi pcbc nvram snd_seq_midi snd_seq_midi_event aesni_intel snd_hda_codec_realtek snd_hda_codec_generic snd_rawmidi aes_x86_64 crypto_simd glue_helper snd_hda_intel snd_hda_codec cryptd intel_cstate arc4 snd_hda_core snd_seq snd_seq_device snd_hwdep iwldvm intel_rapl_perf mac80211 joydev input_leds iwlwifi serio_raw cfg80211 snd_pcm shpchp snd_timer snd mac_hid mei_me lpc_ich mei soundcore sunrpc parport_pc ppdev lp parport autofs4 i915 psmouse e1000e ahci libahci i2c_algo_bit sdhci_pci ptp drm_kms_helper sdhci pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops drm wmi video cpu: 1 pid: 4450 comm: dlm_test.exe not tainted 4.12.4-041204-generic hardware name: lenovo 232425u/232425u, bios g2et82ww (2.02 ) 09/11/2012 task: ffff96b0cbabe140 task.stack: ffffb199027d0000 rip: 0010:sysfs_warn_dup+0x56/0x70 rsp: 0018:ffffb199027d3c58 eflags: 00010282 rax: 0000000000000038 rbx: ffff96b0e2c49158 rcx: 0000000000000006 rdx: 0000000000000000 rsi: 0000000000000086 rdi: ffff96b15e24dcc0 rbp: ffffb199027d3c70 r08: 0000000000000001 r09: 0000000000000721 r10: ffffb199027d3c00 r11: 0000000000000721 r12: ffffb199027d3cd1 r13: ffff96b1592088f0 r14: 0000000000000001 r15: ffffffffffffffef fs: 00007f78069c0700(0000) gs:ffff96b15e240000(0000) knlgs:0000000000000000 cs: 0010 ds: 0000 es: 0000 cr0: 0000000080050033 cr2: 000000178625ed28 cr3: 0000000091d3e000 cr4: 00000000001406e0 call trace: sysfs_do_create_link_sd.isra.2+0x9e/0xb0 sysfs_create_link+0x25/0x40 device_add+0x5a9/0x640 device_create_groups_vargs+0xe0/0xf0 device_create_with_groups+0x3f/0x60 ? snprintf+0x45/0x70 misc_register+0x140/0x180 device_write+0x6a8/0x790 [dlm] __vfs_write+0x37/0x160 ? apparmor_file_permission+0x1a/0x20 ? security_file_permission+0x3b/0xc0 vfs_write+0xb5/0x1a0 sys_write+0x55/0xc0 ? sys_fcntl+0x5d/0xb0 entry_syscall_64_fastpath+0x1e/0xa9 rip: 0033:0x7f78083454bd rsp: 002b:00007f78069bbd30 eflags: 00000293 orig_rax: 0000000000000001 rax: ffffffffffffffda rbx: 0000000000000006 rcx: 00007f78083454bd rdx: 000000000000009c rsi: 00007f78069bee00 rdi: 0000000000000005 rbp: 00007f77f8000a20 r08: 000000000000fcf0 r09: 0000000000000032 r10: 0000000000000024 r11: 0000000000000293 r12: 00007f78069bde00 r13: 00007f78069bee00 r14: 000000000000000a r15: 00007f78069bbd70 code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 2c c8 ff ff 4c 89 e2 48 89 de 48 c7 c7 b0 8e 0c a8 e8 41 e8 ed ff <0f> ff 48 89 df e8 00 d5 f4 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84 ---[ end trace 40412246357cc9e0 ]--- dlm: 59f24629-ae39-44e2-9030-397ebc2eda26: leaving the lockspace group... bug: unable to handle kernel null pointer dereference at 0000000000000001 ip: [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 pgd 0 oops: 0000 [#1] smp modules linked in: dlm 8021q garp mrp stp llc openvswitch nf_defrag_ipv6 nf_conntrack libcrc32c iptable_filter dm_multipath crc32_pclmul dm_mod aesni_intel psmouse aes_x86_64 sg ablk_helper cryptd lrw gf128mul glue_helper i2c_piix4 nls_utf8 tpm_tis tpm isofs nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc xen_wdt ip_tables x_tables autofs4 hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi 8139too serio_raw ata_piix 8139cp mii uhci_hcd ehci_pci ehci_hcd libata scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_mod ipv6 cpu: 0 pid: 394 comm: systemd-udevd tainted: g w 4.4.0+0 #1 hardware name: xen hvm domu, bios 4.7.2-2.2 05/11/2017 task: ffff880002410000 ti: ffff88000243c000 task.ti: ffff88000243c000 rip: e030:[<ffffffff811a3b4a>] [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 rsp: e02b:ffff88000243fd90 eflags: 00010202 rax: 0000000000000000 rbx: ffff8800029864d0 rcx: 000000000007b36c rdx: 000000000007b36b rsi: 00000000024000c0 rdi: ffff880036801c00 rbp: ffff88000243fdc0 r08: 0000000000018880 r09: 0000000000000054 r10: 000000000000004a r11: ffff880034ace6c0 r12: 00000000024000c0 r13: ffff880036801c00 r14: 0000000000000001 r15: ffffffff8118dcc2 fs: 00007f0ab77548c0(0000) gs:ffff880036e00000(0000) knlgs:0000000000000000 cs: e033 ds: 0000 es: 0000 cr0: 0000000080050033 cr2: 0000000000000001 cr3: 000000000332d000 cr4: 0000000000040660 stack: ffffffff8118dc90 ffff8800029864d0 0000000000000000 ffff88003430b0b0 ffff880034b78320 ffff88003430b0b0 ffff88000243fdf8 ffffffff8118dcc2 ffff8800349c6700 ffff8800029864d0 000000000000000b 00007f0ab7754b90 call trace: [<ffffffff8118dc90>] ? anon_vma_fork+0x60/0x140 [<ffffffff8118dcc2>] anon_vma_fork+0x92/0x140 [<ffffffff8107033e>] copy_process+0xcae/0x1a80 [<ffffffff8107128b>] _do_fork+0x8b/0x2d0 [<ffffffff81071579>] sys_clone+0x19/0x20 [<ffffffff815a30ae>] entry_syscall_64_fastpath+0x12/0x71 ] code: f6 75 1c 4c 89 fa 44 89 e6 4c 89 ef e8 a7 e4 00 00 41 f7 c4 00 80 00 00 49 89 c6 74 47 eb 32 49 63 45 20 48 8d 4a 01 4d 8b 45 00 <49> 8b 1c 06 4c 89 f0 65 49 0f c7 08 0f 94 c0 84 c0 74 ac 49 63 rip [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 rsp <ffff88000243fd90> cr2: 0000000000000001 --[ end trace 70cb9fd1b164a0e8 ]-- Signed-off-by: Edwin Török <edvin.torok@citrix.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.
The theory lockdep comes up with is as follows:
(1) If the pagefault handler decides it needs to read pages from AFS, it
calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
creating a call requires the socket lock:
mmap_sem must be taken before sk_lock-AF_RXRPC
(2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind()
binds the underlying UDP socket whilst holding its socket lock.
inet_bind() takes its own socket lock:
sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET
(3) Reading from a TCP socket into a userspace buffer might cause a fault
and thus cause the kernel to take the mmap_sem, but the TCP socket is
locked whilst doing this:
sk_lock-AF_INET must be taken before mmap_sem
However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks. The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace. This is
a limitation in the design of lockdep.
Fix the general case by:
(1) Double up all the locking keys used in sockets so that one set are
used if the socket is created by userspace and the other set is used
if the socket is created by the kernel.
(2) Store the kern parameter passed to sk_alloc() in a variable in the
sock struct (sk_kern_sock). This informs sock_lock_init(),
sock_init_data() and sk_clone_lock() as to the lock keys to be used.
Note that the child created by sk_clone_lock() inherits the parent's
kern setting.
(3) Add a 'kern' parameter to ->accept() that is analogous to the one
passed in to ->create() that distinguishes whether kernel_accept() or
sys_accept4() was the caller and can be passed to sk_alloc().
Note that a lot of accept functions merely dequeue an already
allocated socket. I haven't touched these as the new socket already
exists before we get the parameter.
Note also that there are a couple of places where I've made the accepted
socket unconditionally kernel-based:
irda_accept()
rds_rcp_accept_one()
tcp_accept_from_sock()
because they follow a sock_create_kern() and accept off of that.
Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal. I wonder if these should do that so
that they use the new set of lock keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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>
No point in going through loops and hoops instead of just comparing the values. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
ktime_set(S,N) was required for the timespec storage type and is still useful for situations where a Seconds and Nanoseconds part of a time value needs to be converted. For anything where the Seconds argument is 0, this is pointless and can be replaced with a simple assignment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull dlm fixes from David Teigland: "This set fixes error reporting for dlm sockets, removes the unbound property on the dlm callback workqueue to improve performance, and includes a couple trivial changes" * tag 'dlm-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm: dlm: fix error return code in sctp_accept_from_sock() dlm: don't specify WQ_UNBOUND for the ast callback workqueue dlm: remove lock_sock to avoid scheduling while atomic dlm: don't save callbacks after accept dlm: audit and remove any unnecessary uses of module.h dlm: make genl_ops const
Now genl_register_family() is the only thing (other than the users themselves, perhaps, but I didn't find any doing that) writing to the family struct. In all families that I found, genl_register_family() is only called from __init functions (some indirectly, in which case I've add __init annotations to clarifly things), so all can actually be marked __ro_after_init. This protects the data structure from accidental corruption. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of providing macros/inline functions to initialize the families, make all users initialize them statically and get rid of the macros. This reduces the kernel code size by about 1.6k on x86-64 (with allyesconfig). Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Static family IDs have never really been used, the only use case was the workaround I introduced for those users that assumed their family ID was also their multicast group ID. Additionally, because static family IDs would never be reserved by the generic netlink code, using a relatively low ID would only work for built-in families that can be registered immediately after generic netlink is started, which is basically only the control family (apart from the workaround code, which I also had to add code for so it would reserve those IDs) Thus, anything other than GENL_ID_GENERATE is flawed and luckily not used except in the cases I mentioned. Move those workarounds into a few lines of code, and then get rid of GENL_ID_GENERATE entirely, making it more robust. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>