* [syzbot] KASAN: use-after-free Read in em28xx_close_extension
@ 2021-07-14 14:27 syzbot
[not found] ` <20210727100151.2051-1-hdanton@sina.com>
2021-10-01 8:55 ` syzbot
0 siblings, 2 replies; 6+ messages in thread
From: syzbot @ 2021-07-14 14:27 UTC (permalink / raw)
To: hverkuil-cisco, igormtorrente, linux-kernel, linux-media,
mchehab+huawei, mchehab, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 3dbdb38e Merge branch 'for-5.14' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=158cf1e2300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a1fcf15a09815757
dashboard link: https://syzkaller.appspot.com/bug?extid=005037419ebdf14e1d87
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169746b0300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=157e89c4300000
The issue was bisected to:
commit ac5688637144644f06ed1f3c6d4dd8bb7db96020
Author: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
Date: Tue May 4 18:32:49 2021 +0000
media: em28xx: Fix possible memory leak of em28xx struct
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1742cffc300000
final oops: https://syzkaller.appspot.com/x/report.txt?x=14c2cffc300000
console output: https://syzkaller.appspot.com/x/log.txt?x=10c2cffc300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+005037419ebdf14e1d87@syzkaller.appspotmail.com
Fixes: ac5688637144 ("media: em28xx: Fix possible memory leak of em28xx struct")
usb 1-1: bad CDC descriptors
usb 1-1: USB disconnect, device number 2
em28xx 1-1:64.138: Disconnecting em28xx
em28xx 1-1:64.138: Closing input extension
em28xx 1-1:64.138: Freeing device
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xcc/0xf0 lib/list_debug.c:42
Read of size 8 at addr ffff888021aa8258 by task kworker/1:2/3456
CPU: 1 PID: 3456 Comm: kworker/1:2 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:96
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
__list_del_entry_valid+0xcc/0xf0 lib/list_debug.c:42
__list_del_entry include/linux/list.h:132 [inline]
list_del include/linux/list.h:146 [inline]
em28xx_close_extension+0x10b/0x2a0 drivers/media/usb/em28xx/em28xx-core.c:1146
em28xx_usb_disconnect.cold+0x14b/0x237 drivers/media/usb/em28xx/em28xx-cards.c:4140
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
__device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1181
device_release_driver_internal drivers/base/dd.c:1212 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1235
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533
device_del+0x502/0xd40 drivers/base/core.c:3512
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1413
usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
hub_port_connect drivers/usb/core/hub.c:5129 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5418 [inline]
port_event drivers/usb/core/hub.c:5564 [inline]
hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5646
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
process_scheduled_works kernel/workqueue.c:2338 [inline]
worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
The buggy address belongs to the page:
page:ffffea000086aa00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21aa8
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0000ac0d08 ffff8880b9d3b288 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 3456, ts 70583523123, free_ts 71218691485
prep_new_page mm/page_alloc.c:2445 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4178
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5386
alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272
kmalloc_order+0x34/0xf0 mm/slab_common.c:945
kmalloc_order_trace+0x14/0x120 mm/slab_common.c:961
kmalloc_large include/linux/slab.h:520 [inline]
kmalloc include/linux/slab.h:584 [inline]
kzalloc include/linux/slab.h:721 [inline]
em28xx_usb_probe+0x1f7/0xd00 drivers/media/usb/em28xx/em28xx-cards.c:3855
usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
really_probe+0x291/0xf60 drivers/base/dd.c:576
driver_probe_device+0x298/0x410 drivers/base/dd.c:763
__device_attach_driver+0x203/0x2c0 drivers/base/dd.c:870
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
__device_attach+0x228/0x4a0 drivers/base/dd.c:938
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
device_add+0xbe0/0x2100 drivers/base/core.c:3324
usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164
usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1355 [inline]
free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1406
free_unref_page_prepare mm/page_alloc.c:3341 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3420
__refcount_sub_and_test include/linux/refcount.h:282 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
kref_put.constprop.0.isra.0+0x3d/0x7e include/linux/kref.h:64
em28xx_ir_fini.cold+0x7c/0x120 drivers/media/usb/em28xx/em28xx-input.c:875
em28xx_close_extension+0xc9/0x2a0 drivers/media/usb/em28xx/em28xx-core.c:1143
em28xx_usb_disconnect.cold+0x14b/0x237 drivers/media/usb/em28xx/em28xx-cards.c:4140
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
__device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1181
device_release_driver_internal drivers/base/dd.c:1212 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1235
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533
device_del+0x502/0xd40 drivers/base/core.c:3512
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1413
usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2221
hub_port_connect drivers/usb/core/hub.c:5129 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5418 [inline]
port_event drivers/usb/core/hub.c:5564 [inline]
hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5646
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
process_scheduled_works kernel/workqueue.c:2338 [inline]
worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424
Memory state around the buggy address:
ffff888021aa8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888021aa8180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888021aa8200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888021aa8280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888021aa8300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <20210727100151.2051-1-hdanton@sina.com>]
* Re: [syzbot] KASAN: use-after-free Read in em28xx_close_extension [not found] ` <20210727100151.2051-1-hdanton@sina.com> @ 2021-07-27 14:14 ` Dan Carpenter 2021-07-27 15:13 ` Dongliang Mu 2021-07-28 13:39 ` Dan Carpenter 0 siblings, 2 replies; 6+ messages in thread From: Dan Carpenter @ 2021-07-27 14:14 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, igormtorrente, linux-kernel, linux-media, syzkaller-bugs On Tue, Jul 27, 2021 at 06:01:51PM +0800, Hillf Danton wrote: > Along the probe path, > > em28xx_usb_probe > dev = kzalloc(sizeof(*dev), GFP_KERNEL); > retval = em28xx_init_dev(dev, udev, intf, nr); > em28xx_init_extension(dev); > em28xx_ir_init(struct em28xx *dev) > kref_get(&dev->ref); > > kref_init(&dev->ref); Good detective work. I've created a Smatch check to try find these. It uses the fact that Smatch creates a bunch of fake assignments to set all the struct members of "dev" to zero. Then it uses the modification hook to find the kref_init(). Those are sort of new uses for those hooks so that's quite fun. I'll test it out overnight and see how it works. drivers/media/usb/em28xx/em28xx-cards.c:4086 em28xx_usb_probe() warn: kref has already been modifed (see line 3979) regards, dan carpenter #include "smatch.h" #include "smatch_slist.h" #include "smatch_extra.h" static int my_id; STATE(fresh); static int get_line(struct sm_state *sm) { struct sm_state *tmp; int line = 0; FOR_EACH_PTR(sm->possible, tmp) { if (tmp->state == &undefined && tmp->line > line) line = tmp->line; } END_FOR_EACH_PTR(tmp); if (!line) return sm->line; return line; } static void match_modify(struct sm_state *sm, struct expression *mod_expr) { if (sm->state != &fresh && mod_expr && mod_expr->type == EXPR_CALL && sym_name_is("kref_init", mod_expr->fn)) sm_warning("kref has already been modifed (see line %d)", get_line(sm)); set_state(my_id, sm->name, sm->sym, &undefined); } static bool is_alloc(struct expression *expr) { static struct expression *ignore, *alloc_expr; struct expression *right; if (!expr || expr->type != EXPR_ASSIGNMENT || expr->op != '=') return false; if (expr == ignore) return false; if (expr == alloc_expr) return true; right = strip_expr(expr->right); if (right->type == EXPR_CALL && (sym_name_is("kzalloc", right->fn) || sym_name_is("kmalloc", right->fn))) { alloc_expr = expr; return true; } ignore = expr; return false; } static void match_assign(struct expression *expr) { char *name; if (!is_alloc(get_faked_expression())) return; name = expr_to_str(expr->left); if (name && strstr(name, "refcount.refs.counter")) set_state_expr(my_id, expr->left, &fresh); free_string(name); } void check_kref_init_too_late(int id) { my_id = id; add_hook(&match_assign, ASSIGNMENT_HOOK_AFTER); add_modification_hook(my_id, &match_modify); } ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] KASAN: use-after-free Read in em28xx_close_extension 2021-07-27 14:14 ` Dan Carpenter @ 2021-07-27 15:13 ` Dongliang Mu 2021-07-27 15:33 ` Dan Carpenter 2021-07-28 13:39 ` Dan Carpenter 1 sibling, 1 reply; 6+ messages in thread From: Dongliang Mu @ 2021-07-27 15:13 UTC (permalink / raw) To: Dan Carpenter Cc: Hillf Danton, syzbot, Igor Matheus Andrade Torrente, linux-kernel, linux-media, syzkaller-bugs On Tue, Jul 27, 2021 at 10:15 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > On Tue, Jul 27, 2021 at 06:01:51PM +0800, Hillf Danton wrote: > > Along the probe path, > > > > em28xx_usb_probe > > dev = kzalloc(sizeof(*dev), GFP_KERNEL); > > retval = em28xx_init_dev(dev, udev, intf, nr); > > em28xx_init_extension(dev); > > em28xx_ir_init(struct em28xx *dev) > > kref_get(&dev->ref); > > > > kref_init(&dev->ref); > Hi Dan, I have developed a patch [1] to fix this crash. Would you like to help me double-check if it correctly fixes the underlying bug? [1] [PATCH v2] [media] em28xx-input: fix refcount bug in em28xx_usb_disconnect https://lkml.org/lkml/2021/7/19/263 > Good detective work. > > I've created a Smatch check to try find these. It uses the fact that > Smatch creates a bunch of fake assignments to set all the struct members > of "dev" to zero. Then it uses the modification hook to find the > kref_init(). Those are sort of new uses for those hooks so that's quite > fun. > > I'll test it out overnight and see how it works. > > drivers/media/usb/em28xx/em28xx-cards.c:4086 em28xx_usb_probe() warn: kref has already been modifed (see line 3979) > > regards, > dan carpenter > > #include "smatch.h" > #include "smatch_slist.h" > #include "smatch_extra.h" > > static int my_id; > > STATE(fresh); > > static int get_line(struct sm_state *sm) > { > struct sm_state *tmp; > int line = 0; > > FOR_EACH_PTR(sm->possible, tmp) { > if (tmp->state == &undefined && > tmp->line > line) > line = tmp->line; > } END_FOR_EACH_PTR(tmp); > > if (!line) > return sm->line; > return line; > } > > static void match_modify(struct sm_state *sm, struct expression *mod_expr) > { > if (sm->state != &fresh && > mod_expr && > mod_expr->type == EXPR_CALL && > sym_name_is("kref_init", mod_expr->fn)) > sm_warning("kref has already been modifed (see line %d)", get_line(sm)); > > set_state(my_id, sm->name, sm->sym, &undefined); > } > > static bool is_alloc(struct expression *expr) > { > static struct expression *ignore, *alloc_expr; > struct expression *right; > > if (!expr || expr->type != EXPR_ASSIGNMENT || expr->op != '=') > return false; > if (expr == ignore) > return false; > if (expr == alloc_expr) > return true; > right = strip_expr(expr->right); > if (right->type == EXPR_CALL && > (sym_name_is("kzalloc", right->fn) || > sym_name_is("kmalloc", right->fn))) { > alloc_expr = expr; > return true; > } > ignore = expr; > return false; > } > > static void match_assign(struct expression *expr) > { > char *name; > > if (!is_alloc(get_faked_expression())) > return; > name = expr_to_str(expr->left); > if (name && strstr(name, "refcount.refs.counter")) > set_state_expr(my_id, expr->left, &fresh); > free_string(name); > } > > void check_kref_init_too_late(int id) > { > my_id = id; > > add_hook(&match_assign, ASSIGNMENT_HOOK_AFTER); > add_modification_hook(my_id, &match_modify); > } > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20210727141455.GM1931%40kadam. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] KASAN: use-after-free Read in em28xx_close_extension 2021-07-27 15:13 ` Dongliang Mu @ 2021-07-27 15:33 ` Dan Carpenter 0 siblings, 0 replies; 6+ messages in thread From: Dan Carpenter @ 2021-07-27 15:33 UTC (permalink / raw) To: Dongliang Mu Cc: Hillf Danton, syzbot, Igor Matheus Andrade Torrente, linux-kernel, linux-media, syzkaller-bugs On Tue, Jul 27, 2021 at 11:13:13PM +0800, Dongliang Mu wrote: > On Tue, Jul 27, 2021 at 10:15 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > On Tue, Jul 27, 2021 at 06:01:51PM +0800, Hillf Danton wrote: > > > Along the probe path, > > > > > > em28xx_usb_probe > > > dev = kzalloc(sizeof(*dev), GFP_KERNEL); > > > retval = em28xx_init_dev(dev, udev, intf, nr); > > > em28xx_init_extension(dev); > > > em28xx_ir_init(struct em28xx *dev) > > > kref_get(&dev->ref); > > > > > > kref_init(&dev->ref); > > > > Hi Dan, > > I have developed a patch [1] to fix this crash. Would you like to help > me double-check if it correctly fixes the underlying bug? > > [1] [PATCH v2] [media] em28xx-input: fix refcount bug in > em28xx_usb_disconnect https://lkml.org/lkml/2021/7/19/263 No one likes to review patches which aren't sent over email... :/ LKML.org doesn't give the message-id so I can't use b4 to download the email. That patch doesn't make any sense. We call kref_get() at the start of the function so we need to call kref_put() at the end. The fact that em28xx_ir_fini() calls kref_put() doesn't matter. We will only call fini if the init() succeeds (hopefully). The em28xx_ir_init() error handling is Ad Hoc Style but I don't see anything outright buggy. I think Hillf's approach is correct. regards, dan carpenter ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] KASAN: use-after-free Read in em28xx_close_extension 2021-07-27 14:14 ` Dan Carpenter 2021-07-27 15:13 ` Dongliang Mu @ 2021-07-28 13:39 ` Dan Carpenter 1 sibling, 0 replies; 6+ messages in thread From: Dan Carpenter @ 2021-07-28 13:39 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, igormtorrente, linux-kernel, linux-media, syzkaller-bugs On Tue, Jul 27, 2021 at 05:14:55PM +0300, Dan Carpenter wrote: > On Tue, Jul 27, 2021 at 06:01:51PM +0800, Hillf Danton wrote: > > Along the probe path, > > > > em28xx_usb_probe > > dev = kzalloc(sizeof(*dev), GFP_KERNEL); > > retval = em28xx_init_dev(dev, udev, intf, nr); > > em28xx_init_extension(dev); > > em28xx_ir_init(struct em28xx *dev) > > kref_get(&dev->ref); > > > > kref_init(&dev->ref); > > Good detective work. > > I've created a Smatch check to try find these. It uses the fact that > Smatch creates a bunch of fake assignments to set all the struct members > of "dev" to zero. Then it uses the modification hook to find the > kref_init(). Those are sort of new uses for those hooks so that's quite > fun. > > I'll test it out overnight and see how it works. My Smatch check didn't find any other bugs, but it only had 3 false positives so I'll keep running it nightly on new code. regards, dan carpenter ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] KASAN: use-after-free Read in em28xx_close_extension 2021-07-14 14:27 [syzbot] KASAN: use-after-free Read in em28xx_close_extension syzbot [not found] ` <20210727100151.2051-1-hdanton@sina.com> @ 2021-10-01 8:55 ` syzbot 1 sibling, 0 replies; 6+ messages in thread From: syzbot @ 2021-10-01 8:55 UTC (permalink / raw) To: dan.carpenter, hdanton, hverkuil-cisco, igormtorrente, linux-fsdevel, linux-kernel, linux-media, mchehab, mudongliangabcd, stephen.s.brennan, syzkaller-bugs, viro syzbot suspects this issue was fixed by commit: commit 0766ec82e5fb26fc5dc6d592bc61865608bdc651 Author: Stephen Brennan <stephen.s.brennan@oracle.com> Date: Wed Sep 1 17:51:41 2021 +0000 namei: Fix use after free in kern_path_locked bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17bf2a03300000 start commit: fa54d366a6e4 Merge tag 'acpi-5.14-rc7' of git://git.kernel.. git tree: upstream kernel config: https://syzkaller.appspot.com/x/.config?x=96f0602203250753 dashboard link: https://syzkaller.appspot.com/bug?extid=005037419ebdf14e1d87 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14c086c5300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12950bee300000 If the result looks correct, please mark the issue as fixed by replying with: #syz fix: namei: Fix use after free in kern_path_locked For information about bisection process see: https://goo.gl/tpsmEJ#bisection ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-10-01 8:55 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-07-14 14:27 [syzbot] KASAN: use-after-free Read in em28xx_close_extension syzbot [not found] ` <20210727100151.2051-1-hdanton@sina.com> 2021-07-27 14:14 ` Dan Carpenter 2021-07-27 15:13 ` Dongliang Mu 2021-07-27 15:33 ` Dan Carpenter 2021-07-28 13:39 ` Dan Carpenter 2021-10-01 8:55 ` syzbot
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