3b5f0d0a2b
commit 33eae65c6f49770fec7a662935d4eb4a6406d24b upstream. A small CIFS buffer (448 bytes) isn't big enough to hold SMB2_QUERY_INFO request along with user's input data from CIFS_QUERY_INFO ioctl. That is, if the user passed an input buffer > 344 bytes, the client will memcpy() off the end of @req->Buffer in SMB2_query_info_init() thus causing the following KASAN splat: BUG: KASAN: slab-out-of-bounds in SMB2_query_info_init+0x242/0x250 [cifs] Write of size 1023 at addr ffff88801308c5a8 by task a.out/1240 CPU: 1 PID: 1240 Comm: a.out 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 ? srso_alias_return_thunk+0x5/0xfbef5 ? __phys_addr+0x46/0x90 kasan_report+0xd8/0x110 ? SMB2_query_info_init+0x242/0x250 [cifs] ? SMB2_query_info_init+0x242/0x250 [cifs] kasan_check_range+0x105/0x1b0 __asan_memcpy+0x3c/0x60 SMB2_query_info_init+0x242/0x250 [cifs] ? __pfx_SMB2_query_info_init+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0xfbef5 ? smb_rqst_len+0xa6/0xc0 [cifs] smb2_ioctl_query_info+0x4f4/0x9a0 [cifs] ? __pfx_smb2_ioctl_query_info+0x10/0x10 [cifs] ? __pfx_cifsConvertToUTF16+0x10/0x10 [cifs] ? kasan_set_track+0x25/0x30 ? srso_alias_return_thunk+0x5/0xfbef5 ? __kasan_kmalloc+0x8f/0xa0 ? srso_alias_return_thunk+0x5/0xfbef5 ? cifs_strndup_to_utf16+0x12d/0x1a0 [cifs] ? __build_path_from_dentry_optional_prefix+0x19d/0x2d0 [cifs] ? __pfx_smb2_ioctl_query_info+0x10/0x10 [cifs] cifs_ioctl+0x11c7/0x1de0 [cifs] ? __pfx_cifs_ioctl+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0xfbef5 ? rcu_is_watching+0x23/0x50 ? srso_alias_return_thunk+0x5/0xfbef5 ? __rseq_handle_notify_resume+0x6cd/0x850 ? __pfx___schedule+0x10/0x10 ? blkcg_iostat_update+0x250/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 ? ksys_write+0xe9/0x170 __x64_sys_ioctl+0xc9/0x100 do_syscall_64+0x47/0xf0 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f893dde49cf Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007ffc03ff4160 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffc03ff4378 RCX: 00007f893dde49cf RDX: 00007ffc03ff41d0 RSI: 00000000c018cf07 RDI: 0000000000000003 RBP: 00007ffc03ff4260 R08: 0000000000000410 R09: 0000000000000001 R10: 00007f893dce7300 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc03ff4388 R14: 00007f893df15000 R15: 0000000000406de0 </TASK> Fix this by increasing size of SMB2_QUERY_INFO request buffers and validating input length to prevent other callers from overflowing @req in SMB2_query_info_init() as well. Fixes: f5b05d622a3e ("cifs: add IOCTL for QUERY_INFO passthrough to userspace") Cc: stable@vger.kernel.org Reported-by: Robert Morris <rtm@csail.mit.edu> Signed-off-by: Paulo Alcantara <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.