| Message ID | 20200605035652.10387-1-qiang.zhang@windriver.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: gadget: function: printer: fix use-after-free in __lock_acquire | expand |
On Fri, Jun 05, 2020 at 11:56:52AM +0800, qiang.zhang@windriver.com wrote: > From: Zqiang <qiang.zhang@windriver.com> > > Fix this by increase object reference count. > > BUG: KASAN: use-after-free in __lock_acquire+0x3fd4/0x4180 > kernel/locking/lockdep.c:3831 > Read of size 8 at addr ffff8880683b0018 by task syz-executor.0/3377 > > CPU: 1 PID: 3377 Comm: syz-executor.0 Not tainted 5.6.11 #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xce/0x128 lib/dump_stack.c:118 > print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 > __kasan_report+0x131/0x1b0 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:641 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 > __lock_acquire+0x3fd4/0x4180 kernel/locking/lockdep.c:3831 > lock_acquire+0x127/0x350 kernel/locking/lockdep.c:4488 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 > printer_ioctl+0x4a/0x110 drivers/usb/gadget/function/f_printer.c:723 > vfs_ioctl fs/ioctl.c:47 [inline] > ksys_ioctl+0xfb/0x130 fs/ioctl.c:763 > __do_sys_ioctl fs/ioctl.c:772 [inline] > __se_sys_ioctl fs/ioctl.c:770 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4531a9 > Code: ed 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 > 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d > 01 f0 ff ff 0f 83 bb 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fd14ad72c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 00000000004531a9 > RDX: fffffffffffffff9 RSI: 000000000000009e RDI: 0000000000000003 > RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bbd61 > R13: 00000000004d0a98 R14: 00007fd14ad736d4 R15: 00000000ffffffff > > Allocated by task 2393: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > __kasan_kmalloc.constprop.3+0xa7/0xd0 mm/kasan/common.c:515 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 > kmem_cache_alloc_trace+0xfa/0x2d0 mm/slub.c:2813 > kmalloc include/linux/slab.h:555 [inline] > kzalloc include/linux/slab.h:669 [inline] > gprinter_alloc+0xa1/0x870 drivers/usb/gadget/function/f_printer.c:1416 > usb_get_function+0x58/0xc0 drivers/usb/gadget/functions.c:61 > config_usb_cfg_link+0x1ed/0x3e0 drivers/usb/gadget/configfs.c:444 > configfs_symlink+0x527/0x11d0 fs/configfs/symlink.c:202 > vfs_symlink+0x33d/0x5b0 fs/namei.c:4201 > do_symlinkat+0x11b/0x1d0 fs/namei.c:4228 > __do_sys_symlinkat fs/namei.c:4242 [inline] > __se_sys_symlinkat fs/namei.c:4239 [inline] > __x64_sys_symlinkat+0x73/0xb0 fs/namei.c:4239 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 3368: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > kasan_set_free_info mm/kasan/common.c:337 [inline] > __kasan_slab_free+0x135/0x190 mm/kasan/common.c:476 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 > slab_free_hook mm/slub.c:1444 [inline] > slab_free_freelist_hook mm/slub.c:1477 [inline] > slab_free mm/slub.c:3034 [inline] > kfree+0xf7/0x410 mm/slub.c:3995 > gprinter_free+0x49/0xd0 drivers/usb/gadget/function/f_printer.c:1353 > usb_put_function+0x38/0x50 drivers/usb/gadget/functions.c:87 > config_usb_cfg_unlink+0x2db/0x3b0 drivers/usb/gadget/configfs.c:485 > configfs_unlink+0x3b9/0x7f0 fs/configfs/symlink.c:250 > vfs_unlink+0x287/0x570 fs/namei.c:4073 > do_unlinkat+0x4f9/0x620 fs/namei.c:4137 > __do_sys_unlink fs/namei.c:4184 [inline] > __se_sys_unlink fs/namei.c:4182 [inline] > __x64_sys_unlink+0x42/0x50 fs/namei.c:4182 > do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8880683b0000 > which belongs to the cache kmalloc-1k of size 1024 > The buggy address is located 24 bytes inside of > 1024-byte region [ffff8880683b0000, ffff8880683b0400) > The buggy address belongs to the page: > page:ffffea0001a0ec00 refcount:1 mapcount:0 mapping:ffff88806c00e300 > index:0xffff8880683b1800 compound_mapcount: 0 > flags: 0x100000000010200(slab|head) > raw: 0100000000010200 0000000000000000 0000000600000001 ffff88806c00e300 > raw: ffff8880683b1800 000000008010000a 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Reported-by: Kyungtae Kim <kt0755@gmail.com> > Signed-off-by: Zqiang <qiang.zhang@windriver.com> > --- > drivers/usb/gadget/function/f_printer.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c > index 9c7ed2539ff7..8ed1295d7e35 100644 > --- a/drivers/usb/gadget/function/f_printer.c > +++ b/drivers/usb/gadget/function/f_printer.c > @@ -31,6 +31,7 @@ > #include <linux/types.h> > #include <linux/ctype.h> > #include <linux/cdev.h> > +#include <linux/kref.h> > > #include <asm/byteorder.h> > #include <linux/io.h> > @@ -64,7 +65,7 @@ struct printer_dev { > struct usb_gadget *gadget; > s8 interface; > struct usb_ep *in_ep, *out_ep; > - > + struct kref kref; > struct list_head rx_reqs; /* List of free RX structs */ > struct list_head rx_reqs_active; /* List of Active RX xfers */ > struct list_head rx_buffers; /* List of completed xfers */ Isn't there already a reference count for this structure? Why not use that instead? If not, should this be done to all gadget drivers? What makes this one unique? thanks, greg k-h
I cannot find a reference count for this structure(printer_dev). In this scenario: When the Character device is still open, if you operate the device through configfs and execute commands like unlink, the resources allocated when the device is bound will be released(printer_dev). After that, if you perform ioctl operation again, it will appear use-after-free. add kref to show that this resource(printer_dev) will also use, until this character device is close. Similar problems can occur in f_hid.c. As for the other gadget drivers, I haven't seen their logical implementation,so I'm not sure thanks, Zqiang On 6/18/20 4:30 PM, Greg KH wrote: > On Fri, Jun 05, 2020 at 11:56:52AM +0800, qiang.zhang@windriver.com wrote: >> From: Zqiang <qiang.zhang@windriver.com> >> >> Fix this by increase object reference count. >> >> BUG: KASAN: use-after-free in __lock_acquire+0x3fd4/0x4180 >> kernel/locking/lockdep.c:3831 >> Read of size 8 at addr ffff8880683b0018 by task syz-executor.0/3377 >> >> CPU: 1 PID: 3377 Comm: syz-executor.0 Not tainted 5.6.11 #1 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:77 [inline] >> dump_stack+0xce/0x128 lib/dump_stack.c:118 >> print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 >> __kasan_report+0x131/0x1b0 mm/kasan/report.c:506 >> kasan_report+0x12/0x20 mm/kasan/common.c:641 >> __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 >> __lock_acquire+0x3fd4/0x4180 kernel/locking/lockdep.c:3831 >> lock_acquire+0x127/0x350 kernel/locking/lockdep.c:4488 >> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] >> _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 >> printer_ioctl+0x4a/0x110 drivers/usb/gadget/function/f_printer.c:723 >> vfs_ioctl fs/ioctl.c:47 [inline] >> ksys_ioctl+0xfb/0x130 fs/ioctl.c:763 >> __do_sys_ioctl fs/ioctl.c:772 [inline] >> __se_sys_ioctl fs/ioctl.c:770 [inline] >> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 >> do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> RIP: 0033:0x4531a9 >> Code: ed 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 >> 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d >> 01 f0 ff ff 0f 83 bb 60 fc ff c3 66 2e 0f 1f 84 00 00 00 00 >> RSP: 002b:00007fd14ad72c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 >> RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 00000000004531a9 >> RDX: fffffffffffffff9 RSI: 000000000000009e RDI: 0000000000000003 >> RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004bbd61 >> R13: 00000000004d0a98 R14: 00007fd14ad736d4 R15: 00000000ffffffff >> >> Allocated by task 2393: >> save_stack+0x21/0x90 mm/kasan/common.c:72 >> set_track mm/kasan/common.c:80 [inline] >> __kasan_kmalloc.constprop.3+0xa7/0xd0 mm/kasan/common.c:515 >> kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 >> kmem_cache_alloc_trace+0xfa/0x2d0 mm/slub.c:2813 >> kmalloc include/linux/slab.h:555 [inline] >> kzalloc include/linux/slab.h:669 [inline] >> gprinter_alloc+0xa1/0x870 drivers/usb/gadget/function/f_printer.c:1416 >> usb_get_function+0x58/0xc0 drivers/usb/gadget/functions.c:61 >> config_usb_cfg_link+0x1ed/0x3e0 drivers/usb/gadget/configfs.c:444 >> configfs_symlink+0x527/0x11d0 fs/configfs/symlink.c:202 >> vfs_symlink+0x33d/0x5b0 fs/namei.c:4201 >> do_symlinkat+0x11b/0x1d0 fs/namei.c:4228 >> __do_sys_symlinkat fs/namei.c:4242 [inline] >> __se_sys_symlinkat fs/namei.c:4239 [inline] >> __x64_sys_symlinkat+0x73/0xb0 fs/namei.c:4239 >> do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> >> Freed by task 3368: >> save_stack+0x21/0x90 mm/kasan/common.c:72 >> set_track mm/kasan/common.c:80 [inline] >> kasan_set_free_info mm/kasan/common.c:337 [inline] >> __kasan_slab_free+0x135/0x190 mm/kasan/common.c:476 >> kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 >> slab_free_hook mm/slub.c:1444 [inline] >> slab_free_freelist_hook mm/slub.c:1477 [inline] >> slab_free mm/slub.c:3034 [inline] >> kfree+0xf7/0x410 mm/slub.c:3995 >> gprinter_free+0x49/0xd0 drivers/usb/gadget/function/f_printer.c:1353 >> usb_put_function+0x38/0x50 drivers/usb/gadget/functions.c:87 >> config_usb_cfg_unlink+0x2db/0x3b0 drivers/usb/gadget/configfs.c:485 >> configfs_unlink+0x3b9/0x7f0 fs/configfs/symlink.c:250 >> vfs_unlink+0x287/0x570 fs/namei.c:4073 >> do_unlinkat+0x4f9/0x620 fs/namei.c:4137 >> __do_sys_unlink fs/namei.c:4184 [inline] >> __se_sys_unlink fs/namei.c:4182 [inline] >> __x64_sys_unlink+0x42/0x50 fs/namei.c:4182 >> do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> >> The buggy address belongs to the object at ffff8880683b0000 >> which belongs to the cache kmalloc-1k of size 1024 >> The buggy address is located 24 bytes inside of >> 1024-byte region [ffff8880683b0000, ffff8880683b0400) >> The buggy address belongs to the page: >> page:ffffea0001a0ec00 refcount:1 mapcount:0 mapping:ffff88806c00e300 >> index:0xffff8880683b1800 compound_mapcount: 0 >> flags: 0x100000000010200(slab|head) >> raw: 0100000000010200 0000000000000000 0000000600000001 ffff88806c00e300 >> raw: ffff8880683b1800 000000008010000a 00000001ffffffff 0000000000000000 >> page dumped because: kasan: bad access detected >> >> Reported-by: Kyungtae Kim <kt0755@gmail.com> >> Signed-off-by: Zqiang <qiang.zhang@windriver.com> >> --- >> drivers/usb/gadget/function/f_printer.c | 16 ++++++++++++++-- >> 1 file changed, 14 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c >> index 9c7ed2539ff7..8ed1295d7e35 100644 >> --- a/drivers/usb/gadget/function/f_printer.c >> +++ b/drivers/usb/gadget/function/f_printer.c >> @@ -31,6 +31,7 @@ >> #include <linux/types.h> >> #include <linux/ctype.h> >> #include <linux/cdev.h> >> +#include <linux/kref.h> >> >> #include <asm/byteorder.h> >> #include <linux/io.h> >> @@ -64,7 +65,7 @@ struct printer_dev { >> struct usb_gadget *gadget; >> s8 interface; >> struct usb_ep *in_ep, *out_ep; >> - >> + struct kref kref; >> struct list_head rx_reqs; /* List of free RX structs */ >> struct list_head rx_reqs_active; /* List of Active RX xfers */ >> struct list_head rx_buffers; /* List of completed xfers */ > > Isn't there already a reference count for this structure? Why not use > that instead? > > If not, should this be done to all gadget drivers? What makes this one > unique? > > thanks, > > greg k-h >
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c index 9c7ed2539ff7..8ed1295d7e35 100644 --- a/drivers/usb/gadget/function/f_printer.c +++ b/drivers/usb/gadget/function/f_printer.c @@ -31,6 +31,7 @@ #include <linux/types.h> #include <linux/ctype.h> #include <linux/cdev.h> +#include <linux/kref.h> #include <asm/byteorder.h> #include <linux/io.h> @@ -64,7 +65,7 @@ struct printer_dev { struct usb_gadget *gadget; s8 interface; struct usb_ep *in_ep, *out_ep; - + struct kref kref; struct list_head rx_reqs; /* List of free RX structs */ struct list_head rx_reqs_active; /* List of Active RX xfers */ struct list_head rx_buffers; /* List of completed xfers */ @@ -218,6 +219,13 @@ static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget, /*-------------------------------------------------------------------------*/ +static void printer_dev_free(struct kref *kref) +{ + struct printer_dev *dev = container_of(kref, struct printer_dev, kref); + + kfree(dev); +} + static struct usb_request * printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags) { @@ -348,6 +356,7 @@ printer_open(struct inode *inode, struct file *fd) spin_unlock_irqrestore(&dev->lock, flags); + kref_get(&dev->kref); DBG(dev, "printer_open returned %x\n", ret); return ret; } @@ -365,6 +374,7 @@ printer_close(struct inode *inode, struct file *fd) dev->printer_status &= ~PRINTER_SELECTED; spin_unlock_irqrestore(&dev->lock, flags); + kref_put(&dev->kref, printer_dev_free); DBG(dev, "printer_close\n"); return 0; @@ -1350,7 +1360,8 @@ static void gprinter_free(struct usb_function *f) struct f_printer_opts *opts; opts = container_of(f->fi, struct f_printer_opts, func_inst); - kfree(dev); + + kref_put(&dev->kref, printer_dev_free); mutex_lock(&opts->lock); --opts->refcnt; mutex_unlock(&opts->lock); @@ -1419,6 +1430,7 @@ static struct usb_function *gprinter_alloc(struct usb_function_instance *fi) return ERR_PTR(-ENOMEM); } + kref_init(&dev->kref); ++opts->refcnt; dev->minor = opts->minor; dev->pnp_string = opts->pnp_string;