Commits
Eiichi Tsukata committed d8655e7630d
EDAC: Fix global-out-of-bounds write when setting edac_mc_poll_msec
Commit 9da21b1509d8 ("EDAC: Poll timeout cannot be zero, p2") assumes
edac_mc_poll_msec to be unsigned long, but the type of the variable still
remained as int. Setting edac_mc_poll_msec can trigger out-of-bounds
write.
Reproducer:
# echo 1001 > /sys/module/edac_core/parameters/edac_mc_poll_msec
KASAN report:
BUG: KASAN: global-out-of-bounds in edac_set_poll_msec+0x140/0x150
Write of size 8 at addr ffffffffb91b2d00 by task bash/1996
CPU: 1 PID: 1996 Comm: bash Not tainted 5.2.0-rc6+ #23
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
Call Trace:
dump_stack+0xca/0x13e
print_address_description.cold+0x5/0x246
__kasan_report.cold+0x75/0x9a
? edac_set_poll_msec+0x140/0x150
kasan_report+0xe/0x20
edac_set_poll_msec+0x140/0x150
? dimmdev_location_show+0x30/0x30
? vfs_lock_file+0xe0/0xe0
? _raw_spin_lock+0x87/0xe0
param_attr_store+0x1b5/0x310
? param_array_set+0x4f0/0x4f0
module_attr_store+0x58/0x80
? module_attr_show+0x80/0x80
sysfs_kf_write+0x13d/0x1a0
kernfs_fop_write+0x2bc/0x460
? sysfs_kf_bin_read+0x270/0x270
? kernfs_notify+0x1f0/0x1f0
__vfs_write+0x81/0x100
vfs_write+0x1e1/0x560
ksys_write+0x126/0x250
? __ia32_sys_read+0xb0/0xb0
? do_syscall_64+0x1f/0x390
do_syscall_64+0xc1/0x390
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa7caa5e970
Code: 73 01 c3 48 8b 0d 28 d5 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 99 2d 2c 00 00 75 10 b8 01 00 00 00 04
RSP: 002b:00007fff6acfdfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa7caa5e970
RDX: 0000000000000005 RSI: 0000000000e95c08 RDI: 0000000000000001
RBP: 0000000000e95c08 R08: 00007fa7cad1e760 R09: 00007fa7cb36a700
R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000005
R13: 0000000000000001 R14: 00007fa7cad1d600 R15: 0000000000000005
The buggy address belongs to the variable:
edac_mc_poll_msec+0x0/0x40
Memory state around the buggy address:
ffffffffb91b2c00: 00 00 00 00 fa fa fa fa 00 00 00 00 fa fa fa fa
ffffffffb91b2c80: 00 00 00 00 fa fa fa fa 00 00 00 00 fa fa fa fa
>ffffffffb91b2d00: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
^
ffffffffb91b2d80: 04 fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
ffffffffb91b2e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Fix it by changing the type of edac_mc_poll_msec to unsigned int.
The reason why this patch adopts unsigned int rather than unsigned long
is msecs_to_jiffies() assumes arg to be unsigned int. We can avoid
integer conversion bugs and unsigned int will be large enough for
edac_mc_poll_msec.
Reviewed-by: James Morse <james.morse@arm.com>
Fixes: 9da21b1509d8 ("EDAC: Poll timeout cannot be zero, p2")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>