mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-21 10:01:00 +00:00
Code Issues Releases Wiki Activity
No description
1055063 commits 105 branches 5097 tags 5.5 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
Find a file
David Howells 2bc769b8ed rxrpc: Fix locking in rxrpc's sendmsg 
[ Upstream commit b0f571ecd7 ]

Fix three bugs in the rxrpc's sendmsg implementation:

 (1) rxrpc_new_client_call() should release the socket lock when returning
     an error from rxrpc_get_call_slot().

 (2) rxrpc_wait_for_tx_window_intr() will return without the call mutex
     held in the event that we're interrupted by a signal whilst waiting
     for tx space on the socket or relocking the call mutex afterwards.

     Fix this by: (a) moving the unlock/lock of the call mutex up to
     rxrpc_send_data() such that the lock is not held around all of
     rxrpc_wait_for_tx_window*() and (b) indicating to higher callers
     whether we're return with the lock dropped.  Note that this means
     recvmsg() will not block on this call whilst we're waiting.

 (3) After dropping and regaining the call mutex, rxrpc_send_data() needs
     to go and recheck the state of the tx_pending buffer and the
     tx_total_len check in case we raced with another sendmsg() on the same
     call.

Thinking on this some more, it might make sense to have different locks for
sendmsg() and recvmsg().  There's probably no need to make recvmsg() wait
for sendmsg().  It does mean that recvmsg() can return MSG_EOR indicating
that a call is dead before a sendmsg() to that call returns - but that can
currently happen anyway.

Without fix (2), something like the following can be induced:

	WARNING: bad unlock balance detected!
	5.16.0-rc6-syzkaller #0 Not tainted
	-------------------------------------
	syz-executor011/3597 is trying to release lock (&call->user_mutex) at:
	[<ffffffff885163a3>] rxrpc_do_sendmsg+0xc13/0x1350 net/rxrpc/sendmsg.c:748
	but there are no more locks to release!

	other info that might help us debug this:
	no locks held by syz-executor011/3597.
	...
	Call Trace:
	 <TASK>
	 __dump_stack lib/dump_stack.c:88 [inline]
	 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
	 print_unlock_imbalance_bug include/trace/events/lock.h:58 [inline]
	 __lock_release kernel/locking/lockdep.c:5306 [inline]
	 lock_release.cold+0x49/0x4e kernel/locking/lockdep.c:5657
	 __mutex_unlock_slowpath+0x99/0x5e0 kernel/locking/mutex.c:900
	 rxrpc_do_sendmsg+0xc13/0x1350 net/rxrpc/sendmsg.c:748
	 rxrpc_sendmsg+0x420/0x630 net/rxrpc/af_rxrpc.c:561
	 sock_sendmsg_nosec net/socket.c:704 [inline]
	 sock_sendmsg+0xcf/0x120 net/socket.c:724
	 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
	 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
	 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
	 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
	 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

[Thanks to Hawkins Jiawei and Khalid Masum for their attempts to fix this]

Fixes: bc5e3a546d ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals")
Reported-by: syzbot+7f0483225d0c94cb3441@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: syzbot+7f0483225d0c94cb3441@syzkaller.appspotmail.com
cc: Hawkins Jiawei <yin31149@gmail.com>
cc: Khalid Masum <khalid.masum.92@gmail.com>
cc: Dan Carpenter <dan.carpenter@oracle.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/166135894583.600315.7170979436768124075.stgit@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:16:45 +02:00
arch riscv: lib: uaccess: fix CSR_STATUS SR_SUM bit 2022-08-31 17:16:36 +02:00
block block: don't allow the same type rq_qos add more than once 2022-08-17 14:24:24 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto KEYS: asymmetric: enforce SM2 signature use pkey algo 2022-08-17 14:24:28 +02:00
Documentation net: Fix data-races around netdev_max_backlog. 2022-08-31 17:16:42 +02:00
drivers i40e: Fix incorrect address type for IPv6 flow rules 2022-08-31 17:16:45 +02:00
fs ntfs: fix acl handling 2022-08-31 17:16:38 +02:00
include net: Fix data-races around sysctl_devconf_inherit_init_net. 2022-08-31 17:16:44 +02:00
init stack: Declare {randomize_,}kstack_offset to fix Sparse warnings 2022-08-17 14:23:10 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:23:10 +02:00
kernel kernel/sys_ni: add compat entry for fadvise64_64 2022-08-31 17:16:33 +02:00
lib ratelimit: Fix data-races in ___ratelimit(). 2022-08-31 17:16:43 +02:00
LICENSES
mm mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region 2022-08-17 14:23:58 +02:00
net rxrpc: Fix locking in rxrpc's sendmsg 2022-08-31 17:16:45 +02:00
samples samples/landlock: Format with clang-format 2022-06-09 10:23:23 +02:00
scripts modules: Ensure natural alignment for .altinstructions and __bug_table sections 2022-08-25 11:40:41 +02:00
security apparmor: Fix memleak in aa_simple_write_to_buffer() 2022-08-25 11:40:01 +02:00
sound ALSA: control: Use deferred fasync helper 2022-08-25 11:40:44 +02:00
tools selftests/kprobe: Do not test for GRP/ without event failures 2022-08-25 11:40:38 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Unconditionally get a ref to /dev/kvm module when creating a VM 2022-08-25 11:39:53 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Input: goodix - add a goodix.h header file 2022-07-12 16:34:51 +02:00
Makefile Linux 5.15.63 2022-08-25 11:40:49 +02:00
README

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.