714bac80df
commit 0405d4b63d082861f4eaff9d39c78ee9dc34f845 upstream.
syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1]
The handle_bytes value passed in by the reproducing program is equal to 12.
In handle_to_path(), only 12 bytes of memory are allocated for the structure
file_handle->f_handle member, which causes an out-of-bounds access when
accessing the member parent_block of the structure isofs_fid in isofs,
because accessing parent_block requires at least 16 bytes of f_handle.
Here, fh_len is used to indirectly confirm that the value of handle_bytes
is greater than 3 before accessing parent_block.
[1]
BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466
CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x198/0x550 mm/kasan/report.c:521
kasan_report+0xd8/0x138 mm/kasan/report.c:634
__asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523
do_handle_to_path+0xa0/0x198 fs/fhandle.c:257
handle_to_path fs/fhandle.c:385 [inline]
do_handle_open+0x8cc/0xb8c fs/fhandle.c:403
__do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
__se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
__arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Allocated by task 6466:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_noprof+0x32c/0x54c mm/slub.c:4306
kmalloc_noprof include/linux/slab.h:905 [inline]
handle_to_path fs/fhandle.c:357 [inline]
do_handle_open+0x5a4/0xb8c fs/fhandle.c:403
__do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
__se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
__arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Reported-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4d7cd7dd0ce1aa8d5c65
Tested-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/tencent_9C8CB8A7E7C6C512C7065DC98B6EDF6EC606@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulrich Hecht <uli@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.