Hi,
I am testing kernel snapshots on Fedora Rawhide and Today with build
on commit de5cb0dcb74c I saw for the first time "KASAN:
slab-use-after-free in m_next+0x13b".
Unfortunately it is not clear what triggered this problem because it
happened after 21 hour uptime.
Full trace looks like:
input: Noble FoKus Mystique (AVRCP) as /devices/virtual/input/input26
==================================================================
BUG: KASAN: slab-use-after-free in m_next+0x13b/0x170
Read of size 8 at addr ffff8885609b40f0 by task htop/3847
CPU: 14 UID: 1000 PID: 3847 Comm: htop Tainted: G W L
------- --- 6.12.0-0.rc0.20240923gitde5cb0dcb74c.9.fc42.x86_64+debug
#1
Tainted: [W]=WARN, [L]=SOFTLOCKUP
Hardware name: ASUS System Product Name/ROG STRIX B650E-I GAMING WIFI,
BIOS 3040 09/12/2024
Call Trace:
<TASK>
dump_stack_lvl+0x84/0xd0
? m_next+0x13b/0x170
print_report+0x174/0x505
? m_next+0x13b/0x170
? __virt_addr_valid+0x231/0x420
? m_next+0x13b/0x170
kasan_report+0xab/0x180
? m_next+0x13b/0x170
m_next+0x13b/0x170
seq_read_iter+0x8e5/0x1130
seq_read+0x2b4/0x3c0
? __pfx_seq_read+0x10/0x10
? inode_security+0x54/0xf0
? rw_verify_area+0x3b2/0x5e0
vfs_read+0x165/0xa20
? __pfx_vfs_read+0x10/0x10
? ktime_get_coarse_real_ts64+0x41/0xd0
? local_clock_noinstr+0xd/0x100
? __pfx_lock_release+0x10/0x10
ksys_read+0xfb/0x1d0
? __pfx_ksys_read+0x10/0x10
? ktime_get_coarse_real_ts64+0x41/0xd0
do_syscall_64+0x97/0x190
? __lock_acquire+0xdcd/0x62c0
? __pfx___lock_acquire+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
? audit_filter_inodes.part.0+0x12d/0x220
? local_clock_noinstr+0xd/0x100
? __pfx_lock_release+0x10/0x10
? rcu_is_watching+0x12/0xc0
? kfree+0x27c/0x4d0
? audit_reset_context+0x8c5/0xee0
? lockdep_hardirqs_on_prepare+0x171/0x400
? do_syscall_64+0xa3/0x190
? lockdep_hardirqs_on+0x7c/0x100
? do_syscall_64+0xa3/0x190
? do_syscall_64+0xa3/0x190
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4190dcac36
Code: 89 df e8 2d c1 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 15
83 e2 39 83 fa 08 75 0d e8 32 ff ff ff 66 90 48 8b 45 10 0f 05 <48> 8b
5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08
RSP: 002b:00007ffcde82b690 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f4190ce3740 RCX: 00007f4190dcac36
RDX: 0000000000000400 RSI: 000055bf5e823a20 RDI: 0000000000000005
RBP: 00007ffcde82b6a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f4190f44fd0
R13: 00007f4190f44e80 R14: 000055bf5e823e20 R15: 000055bf5ecc9160
</TASK>
Allocated by task 176289:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x6e/0x70
kmem_cache_alloc_noprof+0x15a/0x3d0
vm_area_dup+0x23/0x190
__split_vma+0x137/0xd40
vms_gather_munmap_vmas+0x29d/0xfc0
mmap_region+0x35a/0x1f50
do_mmap+0x8e7/0x1020
vm_mmap_pgoff+0x178/0x2f0
__do_fast_syscall_32+0x86/0x110
do_fast_syscall_32+0x32/0x80
sysret32_from_system_call+0x0/0x4a
Freed by task 0:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x37/0x50
kmem_cache_free+0x1a7/0x5a0
rcu_do_batch+0x3fd/0x1120
rcu_core+0x636/0x9b0
handle_softirqs+0x1e9/0x8d0
__irq_exit_rcu+0xbb/0x1c0
irq_exit_rcu+0xe/0x30
sysvec_apic_timer_interrupt+0xa1/0xd0
asm_sysvec_apic_timer_interrupt+0x1a/0x20
Last potentially related work creation:
kasan_save_stack+0x30/0x50
__kasan_record_aux_stack+0x8e/0xa0
__call_rcu_common.constprop.0+0xf4/0x10d0
vma_complete+0x720/0x10b0
commit_merge+0x42a/0x1310
vma_expand+0x313/0xad0
vma_merge_new_range+0x2cd/0xec0
mmap_region+0x432/0x1f50
do_mmap+0x8e7/0x1020
vm_mmap_pgoff+0x178/0x2f0
__do_fast_syscall_32+0x86/0x110
do_fast_syscall_32+0x32/0x80
sysret32_from_system_call+0x0/0x4a
The buggy address belongs to the object at ffff8885609b40f0
which belongs to the cache vm_area_struct of size 176
The buggy address is located 0 bytes inside of
freed 176-byte region [ffff8885609b40f0, ffff8885609b41a0)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5609b4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88814d36d001
flags: 0x17ffffc0000040(head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 0017ffffc0000040 ffff888108113d40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000220022 00000001f5000000 ffff88814d36d001
head: 0017ffffc0000040 ffff888108113d40 dead000000000100 dead000000000122
head: 0000000000000000 0000000000220022 00000001f5000000 ffff88814d36d001
head: 0017ffffc0000001 ffffea0015826d01 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8885609b3f80: 00 00 00 00 00 00 00 00 00 00 00 00task_mmu 00 00 00 00
ffff8885609b4000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8885609b4080: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb
^
ffff8885609b4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8885609b4180: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00
==================================================================
Disabling lock debugging due to kernel taint
> sh /usr/src/kernels/(uname -r)/scripts/faddr2line /lib/debug/lib/modules/(uname -r)/vmlinux m_next+0x13b
m_next+0x13b/0x170:
proc_get_vma at fs/proc/task_mmu.c:136
(inlined by) m_next at fs/proc/task_mmu.c:187
> cat -n /usr/src/debug/kernel-6.11-8833-gde5cb0dcb74c/linux-6.12.0-0.rc0.20240923gitde5cb0dcb74c.9.fc42.x86_64/fs/proc/task_mmu.c | sed -n '182,192 p'
182 {
183 if (*ppos == -2UL) {
184 *ppos = -1UL;
185 return NULL;
186 }
187 return proc_get_vma(m->private, ppos);
188 }
189
190 static void m_stop(struct seq_file *m, void *v)
191 {
192 struct proc_maps_private *priv = m->private;
> git blame fs/proc/task_mmu.c -L 182,192
Blaming lines: 100% (11/11), done.
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 182) {
c4c84f06285e4 (Matthew Wilcox (Oracle) 2022-09-06 19:48:57 +0000 183)
if (*ppos == -2UL) {
c4c84f06285e4 (Matthew Wilcox (Oracle) 2022-09-06 19:48:57 +0000 184)
*ppos = -1UL;
c4c84f06285e4 (Matthew Wilcox (Oracle) 2022-09-06 19:48:57 +0000 185)
return NULL;
c4c84f06285e4 (Matthew Wilcox (Oracle) 2022-09-06 19:48:57 +0000 186) }
c4c84f06285e4 (Matthew Wilcox (Oracle) 2022-09-06 19:48:57 +0000 187)
return proc_get_vma(m->private, ppos);
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 188) }
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 189)
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 190)
static void m_stop(struct seq_file *m, void *v)
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 191) {
a6198797cc3fd (Matt Mackall 2008-02-04 22:29:03 -0800 192)
struct proc_maps_private *priv = m->private;
Hmm this line hasn't changed for two years.
Machine spec: https://linux-hardware.org/?probe=323b76ce48
I attached below full kernel log and build config.
Can anyone figure out what happened or should we wait for the second
manifestation of this issue?
--
Best Regards,
Mike Gavrilov.
Attachment:
6.12.0-0.rc0.20240923gitde5cb0dcb74c.9.fc42-BUG-KASAN-slab-use-after-free-in-m_next.zip
Description: Zip archive
Attachment:
.config.zip
Description: Zip archive
