3.16.76-rc1 review patch. If anyone has any objections, please let me know.
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From: Eiichi Tsukata devel@etsukata.com
commit d8655e7630dafa88bc37f101640e39c736399771 upstream.
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 [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/edac/edac_mc_sysfs.c | 16 ++++++++-------- drivers/edac/edac_module.h | 2 +- 2 files changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/edac/edac_mc_sysfs.c +++ b/drivers/edac/edac_mc_sysfs.c @@ -26,7 +26,7 @@ static int edac_mc_log_ue = 1; static int edac_mc_log_ce = 1; static int edac_mc_panic_on_ue; -static int edac_mc_poll_msec = 1000; +static unsigned int edac_mc_poll_msec = 1000;
/* Getter functions for above */ int edac_mc_get_log_ue(void) @@ -45,30 +45,30 @@ int edac_mc_get_panic_on_ue(void) }
/* this is temporary */ -int edac_mc_get_poll_msec(void) +unsigned int edac_mc_get_poll_msec(void) { return edac_mc_poll_msec; }
static int edac_set_poll_msec(const char *val, struct kernel_param *kp) { - unsigned long l; + unsigned int i; int ret;
if (!val) return -EINVAL;
- ret = kstrtoul(val, 0, &l); + ret = kstrtouint(val, 0, &i); if (ret) return ret;
- if (l < 1000) + if (i < 1000) return -EINVAL;
- *((unsigned long *)kp->arg) = l; + *((unsigned int *)kp->arg) = i;
/* notify edac_mc engine to reset the poll period */ - edac_mc_reset_delay_period(l); + edac_mc_reset_delay_period(i);
return 0; } @@ -82,7 +82,7 @@ MODULE_PARM_DESC(edac_mc_log_ue, module_param(edac_mc_log_ce, int, 0644); MODULE_PARM_DESC(edac_mc_log_ce, "Log correctable error to console: 0=off 1=on"); -module_param_call(edac_mc_poll_msec, edac_set_poll_msec, param_get_int, +module_param_call(edac_mc_poll_msec, edac_set_poll_msec, param_get_uint, &edac_mc_poll_msec, 0644); MODULE_PARM_DESC(edac_mc_poll_msec, "Polling period in milliseconds");
--- a/drivers/edac/edac_module.h +++ b/drivers/edac/edac_module.h @@ -32,7 +32,7 @@ extern int edac_mc_get_log_ue(void); extern int edac_mc_get_log_ce(void); extern int edac_mc_get_panic_on_ue(void); extern int edac_get_poll_msec(void); -extern int edac_mc_get_poll_msec(void); +extern unsigned int edac_mc_get_poll_msec(void);
unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf, unsigned len);