c0e98de950
commit a8f68b11158f09754418de62e6b3e7b9b7a50cc9 upstream. Validate next header's offset in ->next_header() so that it isn't smaller than MID_HEADER_SIZE(server) and then standard_receive3() or ->receive() ends up writing off the end of the buffer because 'pdu_length - MID_HEADER_SIZE(server)' wraps up to a huge length: BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0x4fc/0x840 Write of size 701 at addr ffff88800caf407f by task cifsd/1090 CPU: 0 PID: 1090 Comm: cifsd Not tainted 6.7.0-rc4 #5 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x4a/0x80 print_report+0xcf/0x650 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __phys_addr+0x46/0x90 kasan_report+0xd8/0x110 ? _copy_to_iter+0x4fc/0x840 ? _copy_to_iter+0x4fc/0x840 kasan_check_range+0x105/0x1b0 __asan_memcpy+0x3c/0x60 _copy_to_iter+0x4fc/0x840 ? srso_alias_return_thunk+0x5/0xfbef5 ? hlock_class+0x32/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx__copy_to_iter+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_is_held_type+0x90/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_resched+0x278/0x360 ? __pfx___might_resched+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 __skb_datagram_iter+0x2c2/0x460 ? __pfx_simple_copy_to_iter+0x10/0x10 skb_copy_datagram_iter+0x6c/0x110 tcp_recvmsg_locked+0x9be/0xf40 ? __pfx_tcp_recvmsg_locked+0x10/0x10 ? mark_held_locks+0x5d/0x90 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_recvmsg+0xe2/0x310 ? __pfx_tcp_recvmsg+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x14a/0x3a0 ? srso_alias_return_thunk+0x5/0xfbef5 inet_recvmsg+0xd0/0x370 ? __pfx_inet_recvmsg+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_trylock+0xd1/0x120 sock_recvmsg+0x10d/0x150 cifs_readv_from_socket+0x25a/0x490 [cifs] ? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0xfbef5 cifs_read_from_socket+0xb5/0x100 [cifs] ? __pfx_cifs_read_from_socket+0x10/0x10 [cifs] ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_trylock+0xd1/0x120 ? _raw_spin_unlock+0x23/0x40 ? srso_alias_return_thunk+0x5/0xfbef5 ? __smb2_find_mid+0x126/0x230 [cifs] cifs_demultiplex_thread+0xd39/0x1270 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] ? __pfx_lock_release+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? mark_held_locks+0x1a/0x90 ? lockdep_hardirqs_on_prepare+0x136/0x210 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __kthread_parkme+0xce/0xf0 ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0x18d/0x1d0 ? kthread+0xdb/0x1d0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> Fixes: 8ce79ec359ad ("cifs: update multiplex loop to handle compounded responses") Cc: stable@vger.kernel.org Reported-by: Robert Morris <rtm@csail.mit.edu> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.