Inject fault while probing kunit-example-test.ko, if kstrdup()
fails in mod_sysfs_setup() in load_module(), the mod->state will
switch from MODULE_STATE_COMING to MODULE_STATE_GOING instead of
from MODULE_STATE_LIVE to MODULE_STATE_GOING, so only
kunit_module_exit() will be called without kunit_module_init(), and
the mod->kunit_suites is no set correctly and the free in
kunit_free_suite_set() will cause below wild-memory-access bug.
The mod->state state machine when load_module() succeeds:
MODULE_STATE_UNFORMED ---> MODULE_STATE_COMING ---> MODULE_STATE_LIVE
^ |
| | delete_module
+---------------- MODULE_STATE_GOING <---------+
The mod->state state machine when load_module() fails at
mod_sysfs_setup():
MODULE_STATE_UNFORMED ---> MODULE_STATE_COMING ---> MODULE_STATE_GOING
^ |
| |
+-----------------------------------------------+
Call kunit_module_init() at MODULE_STATE_COMING state to fix the issue
because MODULE_STATE_LIVE is transformed from it.
Unable to handle kernel paging request at virtual address ffffff341e942a88
KASAN: maybe wild-memory-access in range [0x0003f9a0f4a15440-0x0003f9a0f4a15447]
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000441ea000
[ffffff341e942a88] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in: kunit_example_test(-) cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: kunit_example_test]
CPU: 3 PID: 2035 Comm: modprobe Tainted: G W N 6.5.0-next-20230828+ #136
Hardware name: linux,dummy-virt (DT)
pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kfree+0x2c/0x70
lr : kunit_free_suite_set+0xcc/0x13c
sp : ffff8000829b75b0
x29: ffff8000829b75b0 x28: ffff8000829b7b90 x27: 0000000000000000
x26: dfff800000000000 x25: ffffcd07c82a7280 x24: ffffcd07a50ab300
x23: ffffcd07a50ab2e8 x22: 1ffff00010536ec0 x21: dfff800000000000
x20: ffffcd07a50ab2f0 x19: ffffcd07a50ab2f0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffffcd07c24b6764
x14: ffffcd07c24b63c0 x13: ffffcd07c4cebb94 x12: ffff700010536ec7
x11: 1ffff00010536ec6 x10: ffff700010536ec6 x9 : dfff800000000000
x8 : 00008fffefac913a x7 : 0000000041b58ab3 x6 : 0000000000000000
x5 : 1ffff00010536ec5 x4 : ffff8000829b7628 x3 : dfff800000000000
x2 : ffffff341e942a80 x1 : ffffcd07a50aa000 x0 : fffffc0000000000
Call trace:
kfree+0x2c/0x70
kunit_free_suite_set+0xcc/0x13c
kunit_module_notify+0xd8/0x360
blocking_notifier_call_chain+0xc4/0x128
load_module+0x382c/0x44a4
init_module_from_file+0xd4/0x128
idempotent_init_module+0x2c8/0x524
__arm64_sys_finit_module+0xac/0x100
invoke_syscall+0x6c/0x258
el0_svc_common.constprop.0+0x160/0x22c
do_el0_svc+0x44/0x5c
el0_svc+0x38/0x78
el0t_64_sync_handler+0x13c/0x158
el0t_64_sync+0x190/0x194
Code: aa0003e1 b25657e0 d34cfc42 8b021802 (f9400440)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Oops: Fatal exception
SMP: stopping secondary CPUs
Kernel Offset: 0x4d0742200000 from 0xffff800080000000
PHYS_OFFSET: 0xffffee43c0000000
CPU features: 0x88000203,3c020000,1000421b
Memory Limit: none
Rebooting in 1 seconds..
Fixes: 3d6e44623841 ("kunit: unify module and builtin suite definitions")
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Reviewed-by: Rae Moar <rmoar@xxxxxxxxxx>
Reviewed-by: David Gow <davidgow@xxxxxxxxxx>
---
v2:
- Add Reviewed-by.
- Adjust the 4th patch to be the second.
---
lib/kunit/test.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 49698a168437..421f13981412 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -784,12 +784,13 @@ static int kunit_module_notify(struct notifier_block *nb, unsigned long val,
switch (val) {
case MODULE_STATE_LIVE:
- kunit_module_init(mod);
break;
case MODULE_STATE_GOING:
kunit_module_exit(mod);
break;
case MODULE_STATE_COMING:
+ kunit_module_init(mod);
+ break;
case MODULE_STATE_UNFORMED:
break;
}
--
2.34.1
