Skip to content
Snippets Groups Projects
Select Git revision
0 results
Search by author
  • Any Author
0 authors
  1. Sep 09, 2020
    • Will Deacon's avatar
      media: uvcvideo: Avoid cyclic entity chains due to malformed USB descriptors · 8ce40651
      Will Deacon authored 
      commit 68035c80 upstream.

Way back in 2017, fuzzing the 4.14-rc2 USB stack with syzkaller kicked
up the following WARNING from the UVC chain scanning code:

  | list_add double add: new=ffff880069084010, prev=ffff880069084010,
  | next=ffff880067d22298.
  | ------------[ cut here ]------------
  | WARNING: CPU: 1 PID: 1846 at lib/list_debug.c:31 __list_add_valid+0xbd/0xf0
  | Modules linked in:
  | CPU: 1 PID: 1846 Comm: kworker/1:2 Not tainted
  | 4.14.0-rc2-42613-g1488251d1a98 #238
  | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  | Workqueue: usb_hub_wq hub_event
  | task: ffff88006b01ca40 task.stack: ffff880064358000
  | RIP: 0010:__list_add_valid+0xbd/0xf0 lib/list_debug.c:29
  | RSP: 0018:ffff88006435ddd0 EFLAGS: 00010286
  | RAX: 0000000000000058 RBX: ffff880067d22298 RCX: 0000000000000000
  | RDX: 0000000000000058 RSI: ffffffff85a58800 RDI: ffffed000c86bbac
  | RBP: ffff88006435dde8 R08: 1ffff1000c86ba52 R09: 0000000000000000
  | R10: 0000000000000002 R11: 0000000000000000 R12: ffff880069084010
  | R13: ffff880067d22298 R14: ffff880069084010 R15: ffff880067d222a0
  | FS:  0000000000000000(0000) GS:ffff88006c900000(0000) knlGS:0000000000000000
  | CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  | CR2: 0000000020004ff2 CR3: 000000006b447000 CR4: 00000000000006e0
  | Call Trace:
  |  __list_add ./include/linux/list.h:59
  |  list_add_tail+0x8c/0x1b0 ./include/linux/list.h:92
  |  uvc_scan_chain_forward.isra.8+0x373/0x416
  | drivers/media/usb/uvc/uvc_driver.c:1471
  |  uvc_scan_chain drivers/media/usb/uvc/uvc_driver.c:1585
  |  uvc_scan_device drivers/media/usb/uvc/uvc_driver.c:1769
  |  uvc_probe+0x77f2/0x8f00 drivers/media/usb/uvc/uvc_driver.c:2104

Looking into the output from usbmon, the interesting part is the
following data packet:

  ffff880069c63e00 30710169 C Ci:1:002:0 0 143 = 09028f00 01030080
  00090403 00000e01 00000924 03000103 7c003328 010204db

If we drop the lead configuration and interface descriptors, we're left
with an output terminal descriptor describing a generic display:

  /* Output terminal descriptor */
  buf[0]	09
  buf[1]	24
  buf[2]	03	/* UVC_VC_OUTPUT_TERMINAL */
  buf[3]	00	/* ID */
  buf[4]	01	/* type == 0x0301 (UVC_OTT_DISPLAY) */
  buf[5]	03
  buf[6]	7c
  buf[7]	00	/* source ID refers to self! */
  buf[8]	33

The problem with this descriptor is that it is self-referential: the
source ID of 0 matches itself! This causes the 'struct uvc_entity'
representing the display to be added to its chain list twice during
'uvc_scan_chain()': once via 'uvc_scan_chain_entity()' when it is
processed directly from the 'dev->entities' list and then again
immediately afterwards when trying to follow the source ID in
'uvc_scan_chain_forward()'

Add a check before adding an entity to a chain list to ensure that the
entity is not already part of a chain.

Link: https://lore.kernel.org/linux-media/CAAeHK+z+Si69jUR+N-SjN9q4O+o5KFiNManqEa-PjUta7EOb7A@mail.gmail.com/



Cc: <stable@vger.kernel.org>
Fixes: c0efd232 ("V4L/DVB (8145a): USB Video Class driver")
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2 tags
      8ce40651
  3. Aug 05, 2020
  5. Jul 06, 2020
  7. Jun 05, 2020
    • Jiri Slaby's avatar
      vt: selection, push sel_lock up · c87961ff
      Jiri Slaby authored 
      
commit e8c75a30 upstream.

sel_lock cannot nest in the console lock. Thanks to syzkaller, the
kernel states firmly:

> WARNING: possible circular locking dependency detected
> 5.6.0-rc3-syzkaller #0 Not tainted
> ------------------------------------------------------
> syz-executor.4/20336 is trying to acquire lock:
> ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>
> but task is already holding lock:
> ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374
>
> which lock already depends on the new lock.
>
> the existing dependency chain (in reverse order) is:
>
> -> #2 (sel_lock){+.+.}:
>        mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118
>        set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217
>        set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181
>        tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_SETSEL).
Locks held on the path: console_lock -> sel_lock

> -> #1 (console_lock){+.+.}:
>        console_lock+0x46/0x70 kernel/printk/printk.c:2289
>        con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223
>        n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350
>        do_tty_write drivers/tty/tty_io.c:962 [inline]
>        tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046

This is write().
Locks held on the path: termios_rwsem -> console_lock

> -> #0 (&tty->termios_rwsem){++++}:
>        down_write+0x57/0x140 kernel/locking/rwsem.c:1534
>        tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>        mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902
>        tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465
>        paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389
>        tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_PASTESEL).
Locks held on the path: sel_lock -> termios_rwsem

> other info that might help us debug this:
>
> Chain exists of:
>   &tty->termios_rwsem --> console_lock --> sel_lock

Clearly. From the above, we have:
 console_lock -> sel_lock
 sel_lock -> termios_rwsem
 termios_rwsem -> console_lock

Fix this by reversing the console_lock -> sel_lock dependency in
ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Reported-by: default avatar <syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com>
Fixes: 07e6124a ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ASB-2020-06-05_4.14-p-release
      c87961ff
    • Jiri Slaby's avatar
      vt: selection, push console lock down · e44f1b03
      Jiri Slaby authored 
      
commit 4b70dd57 upstream.

We need to nest the console lock in sel_lock, so we have to push it down
a bit. Fortunately, the callers of set_selection_* just lock the console
lock around the function call. So moving it down is easy.

In the next patch, we switch the order.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Fixes: 07e6124a ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e44f1b03
    • Jiri Slaby's avatar
      vt: selection, close sel_buffer race · 23637eb9
      Jiri Slaby authored 
      
commit 07e6124a upstream.

syzkaller reported this UAF:
BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
Read of size 1 at addr ffff8880089e40e9 by task syz-executor.1/13184

CPU: 0 PID: 13184 Comm: syz-executor.1 Not tainted 5.4.7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
...
 kasan_report+0xe/0x20 mm/kasan/common.c:634
 n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
 tty_ldisc_receive_buf+0xac/0x190 drivers/tty/tty_buffer.c:461
 paste_selection+0x297/0x400 drivers/tty/vt/selection.c:372
 tioclinux+0x20d/0x4e0 drivers/tty/vt/vt.c:3044
 vt_ioctl+0x1bcf/0x28d0 drivers/tty/vt/vt_ioctl.c:364
 tty_ioctl+0x525/0x15a0 drivers/tty/tty_io.c:2657
 vfs_ioctl fs/ioctl.c:47 [inline]

It is due to a race between parallel paste_selection (TIOCL_PASTESEL)
and set_selection_user (TIOCL_SETSEL) invocations. One uses sel_buffer,
while the other frees it and reallocates a new one for another
selection. Add a mutex to close this race.

The mutex takes care properly of sel_buffer and sel_buffer_lth only. The
other selection global variables (like sel_start, sel_end, and sel_cons)
are protected only in set_selection_user. The other functions need quite
some more work to close the races of the variables there. This is going
to happen later.

This likely fixes (I am unsure as there is no reproducer provided) bug
206361 too. It was marked as CVE-2020-8648.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Reported-by: default avatar <syzbot+59997e8d5cbdc486e6f6@syzkaller.appspotmail.com>
References: https://bugzilla.kernel.org/show_bug.cgi?id=206361
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      23637eb9
    • Zhang Xiaoxu's avatar
      vgacon: Fix a UAF in vgacon_invert_region · e2b85653
      Zhang Xiaoxu authored 
      
commit 513dc792 upstream.

When syzkaller tests, there is a UAF:
  BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr
    ffff880000100000
  Read of size 2 by task syz-executor.1/16489
  page:ffffea0000004000 count:0 mapcount:-127 mapping:          (null)
  index:0x0
  page flags: 0xfffff00000000()
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
  Call Trace:
    [<ffffffffb119f309>] dump_stack+0x1e/0x20
    [<ffffffffb04af957>] kasan_report+0x577/0x950
    [<ffffffffb04ae652>] __asan_load2+0x62/0x80
    [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110
    [<ffffffffb0a39d95>] invert_screen+0xe5/0x470
    [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0
    [<ffffffffb0a3bfae>] tioclinux+0xee/0x490
    [<ffffffffb0a1d114>] vt_ioctl+0xff4/0x2670
    [<ffffffffb0a0089a>] tty_ioctl+0x46a/0x1a10
    [<ffffffffb052db3d>] do_vfs_ioctl+0x5bd/0xc40
    [<ffffffffb052e2f2>] SyS_ioctl+0x132/0x170
    [<ffffffffb11c9b1b>] system_call_fastpath+0x22/0x27
    Memory state around the buggy address:
     ffff8800000fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00
     ffff8800000fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00
     00 00 00
    >ffff880000100000: ff ff ff ff ff ff ff ff ff ff ff ff ff
     ff ff ff

It can be reproduce in the linux mainline by the program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <sys/ioctl.h>
  #include <linux/vt.h>

  struct tiocl_selection {
    unsigned short xs;      /* X start */
    unsigned short ys;      /* Y start */
    unsigned short xe;      /* X end */
    unsigned short ye;      /* Y end */
    unsigned short sel_mode; /* selection mode */
  };

  #define TIOCL_SETSEL    2
  struct tiocl {
    unsigned char type;
    unsigned char pad;
    struct tiocl_selection sel;
  };

  int main()
  {
    int fd = 0;
    const char *dev = "/dev/char/4:1";

    struct vt_consize v = {0};
    struct tiocl tioc = {0};

    fd = open(dev, O_RDWR, 0);

    v.v_rows = 3346;
    ioctl(fd, VT_RESIZEX, &v);

    tioc.type = TIOCL_SETSEL;
    ioctl(fd, TIOCLINUX, &tioc);

    return 0;
  }

When resize the screen, update the 'vc->vc_size_row' to the new_row_size,
but when 'set_origin' in 'vgacon_set_origin', vgacon use 'vga_vram_base'
for 'vc_origin' and 'vc_visible_origin', not 'vc_screenbuf'. It maybe
smaller than 'vc_screenbuf'. When TIOCLINUX, use the new_row_size to calc
the offset, it maybe larger than the vga_vram_size in vgacon driver, then
bad access.
Also, if set an larger screenbuf firstly, then set an more larger
screenbuf, when copy old_origin to new_origin, a bad access may happen.

So, If the screen size larger than vga_vram, resize screen should be
failed. This alse fix CVE-2020-8649 and CVE-2020-8647.

Linus pointed out that overflow checking seems absent. We're saved by
the existing bounds checks in vc_do_resize() with rather strict
limits:

	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
		return -EINVAL;

Fixes: 0aec4867 ("[PATCH] SVGATextMode fix")
Reference: CVE-2020-8647 and CVE-2020-8649
Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Signed-off-by: default avatarZhang Xiaoxu <zhangxiaoxu5@huawei.com>
[danvet: augment commit message to point out overflow safety]
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304022429.37738-1-zhangxiaoxu5@huawei.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e2b85653
    • Eric Dumazet's avatar
      net/flow_dissector: switch to siphash · d1d6fe98
      Eric Dumazet authored 
      
commit 55667441 upstream.

UDP IPv6 packets auto flowlabels are using a 32bit secret
(static u32 hashrnd in net/core/flow_dissector.c) and
apply jhash() over fields known by the receivers.

Attackers can easily infer the 32bit secret and use this information
to identify a device and/or user, since this 32bit secret is only
set at boot time.

Really, using jhash() to generate cookies sent on the wire
is a serious security concern.

Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be
a dead end. Trying to periodically change the secret (like in sch_sfq.c)
could change paths taken in the network for long lived flows.

Let's switch to siphash, as we did in commit df453700
("inet: switch IP ID generator to siphash")

Using a cryptographically strong pseudo random function will solve this
privacy issue and more generally remove other weak points in the stack.

Packet schedulers using skb_get_hash_perturb() benefit from this change.

Fixes: b5677416 ("ipv6: Enable auto flow labels by default")
Fixes: 42240901 ("ipv6: Implement different admin modes for automatic flow labels")
Fixes: 67800f9b ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Fixes: cb1ce2ef ("ipv6: Implement automatic flow label generation on transmit")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarJonathan Berger <jonathann1@walla.com>
Reported-by: default avatarAmit Klein <aksecurity@gmail.com>
Reported-by: default avatarBenny Pinkas <benny@pinkas.net>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d1d6fe98
  9. May 15, 2020
    • Florian Fainelli's avatar
      net: phy: broadcom: Use strlcpy() for ethtool::get_strings · 5569c7d7
      Florian Fainelli authored 
      
commit 8a17eefa upstream.

Our statistics strings are allocated at initialization without being
bound to a specific size, yet, we would copy ETH_GSTRING_LEN bytes using
memcpy() which would create out of bounds accesses, this was flagged by
KASAN. Replace this with strlcpy() to make sure we are bound the source
buffer size and we also always NUL-terminate strings.

Fixes: 820ee17b ("net: phy: broadcom: Add support code for reading PHY counters")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5569c7d7
    • Miguel Ojeda's avatar
      include/linux/module.h: copy __init/__exit attrs to init/cleanup_module · 70fb9356
      Miguel Ojeda authored 
      commit a6e60d84 upstream.

The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.

In particular, it triggers for all the init/cleanup_module
aliases in the kernel (defined by the module_init/exit macros),
ending up being very noisy.

These aliases point to the __init/__exit functions of a module,
which are defined as __cold (among other attributes). However,
the aliases themselves do not have the __cold attribute.

Since the compiler behaves differently when compiling a __cold
function as well as when compiling paths leading to calls
to __cold functions, the warning is trying to point out
the possibly-forgotten attribute in the alias.

In order to keep the warning enabled, we decided to silence
this case. Ideally, we would mark the aliases directly
as __init/__exit. However, there are currently around 132 modules
in the kernel which are missing __init/__exit in their init/cleanup
functions (either because they are missing, or for other reasons,
e.g. the functions being called from somewhere else); and
a section mismatch is a hard error.

A conservative alternative was to mark the aliases as __cold only.
However, since we would like to eventually enforce __init/__exit
to be always marked,  we chose to use the new __copy function
attribute (introduced by GCC 9 as well to deal with this).
With it, we copy the attributes used by the target functions
into the aliases. This way, functions that were not marked
as __init/__exit won't have their aliases marked either,
and therefore there won't be a section mismatch.

Note that the warning would go away marking either the extern
declaration, the definition, or both. However, we only mark
the definition of the alias, since we do not want callers
(which only see the declaration) to be compiled as if the function
was __cold (and therefore the paths leading to those calls
would be assumed to be unlikely).

Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/
Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/


Suggested-by: default avatarMartin Sebor <msebor@gcc.gnu.org>
Acked-by: default avatarJessica Yu <jeyu@kernel.org>
Signed-off-by: default avatarMiguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: default avatarStefan Agner <stefan@agner.ch>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      70fb9356
    • Miguel Ojeda's avatar
      Compiler Attributes: add support for __copy (gcc >= 9) · 39eb4fab
      Miguel Ojeda authored 
      commit c0d9782f upstream.

From the GCC manual:

  copy
  copy(function)

    The copy attribute applies the set of attributes with which function
    has been declared to the declaration of the function to which
    the attribute is applied. The attribute is designed for libraries
    that define aliases or function resolvers that are expected
    to specify the same set of attributes as their targets. The copy
    attribute can be used with functions, variables, or types. However,
    the kind of symbol to which the attribute is applied (either
    function or variable) must match the kind of symbol to which
    the argument refers. The copy attribute copies only syntactic and
    semantic attributes but not attributes that affect a symbol’s
    linkage or visibility such as alias, visibility, or weak.
    The deprecated attribute is also not copied.

  https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html



The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target, e.g.:

    void __cold f(void) {}
    void __alias("f") g(void);

diagnoses:

    warning: 'g' specifies less restrictive attribute than
    its target 'f': 'cold' [-Wmissing-attributes]

Using __copy(f) we can copy the __cold attribute from f to g:

    void __cold f(void) {}
    void __copy(f) __alias("f") g(void);

This attribute is most useful to deal with situations where an alias
is declared but we don't know the exact attributes the target has.

For instance, in the kernel, the widely used module_init/exit macros
define the init/cleanup_module aliases, but those cannot be marked
always as __init/__exit since some modules do not have their
functions marked as such.

Suggested-by: default avatarMartin Sebor <msebor@gcc.gnu.org>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarMiguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: default avatarStefan Agner <stefan@agner.ch>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      39eb4fab
  11. May 04, 2020
  13. May 02, 2020
  15. Apr 06, 2020
  17. Mar 04, 2020
    • Suren Baghdasaryan's avatar
      staging: android: ashmem: Disallow ashmem memory from being remapped · acbb2f9f
      Suren Baghdasaryan authored 
      
commit 6d67b029 upstream.

When ashmem file is mmapped, the resulting vma->vm_file points to the
backing shmem file with the generic fops that do not check ashmem
permissions like fops of ashmem do. If an mremap is done on the ashmem
region, then the permission checks will be skipped. Fix that by disallowing
mapping operation on the backing shmem file.

Reported-by: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
Cc: stable <stable@vger.kernel.org> # 4.4,4.9,4.14,4.18,5.4
Signed-off-by: default avatarTodd Kjos <tkjos@google.com>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20200127235616.48920-1-tkjos@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ASB-2020-03-05_4.14-p-release
      acbb2f9f
    • Alan Stern's avatar
      USB: core: Fix races in character device registration and deregistraion · ac81d00e
      Alan Stern authored 
      
commit 303911cf upstream.

The syzbot fuzzer has found two (!) races in the USB character device
registration and deregistration routines.  This patch fixes the races.

The first race results from the fact that usb_deregister_dev() sets
usb_minors[intf->minor] to NULL before calling device_destroy() on the
class device.  This leaves a window during which another thread can
allocate the same minor number but will encounter a duplicate name
error when it tries to register its own class device.  A typical error
message in the system log would look like:

    sysfs: cannot create duplicate filename '/class/usbmisc/ldusb0'

The patch fixes this race by destroying the class device first.

The second race is in usb_register_dev().  When that routine runs, it
first allocates a minor number, then drops minor_rwsem, and then
creates the class device.  If the device creation fails, the minor
number is deallocated and the whole routine returns an error.  But
during the time while minor_rwsem was dropped, there is a window in
which the minor number is allocated and so another thread can
successfully open the device file.  Typically this results in
use-after-free errors or invalid accesses when the other thread closes
its open file reference, because the kernel then tries to release
resources that were already deallocated when usb_register_dev()
failed.  The patch fixes this race by keeping minor_rwsem locked
throughout the entire routine.

Reported-and-tested-by: default avatar <syzbot+30cf45ebfe0b0c4847a1@syzkaller.appspotmail.com>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1908121607590.1659-100000@iolanthe.rowland.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ac81d00e
    • Hillf Danton's avatar
      HID: hiddev: avoid opening a disconnected device · f95f2186
      Hillf Danton authored 
      commit 9c09b214 upstream.

syzbot found the following crash on:

HEAD commit:    e96407b4 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=147ac20c600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=792eb47789f57810
dashboard link: https://syzkaller.appspot.com/bug?extid=62a1e04fd3ec2abf099e


compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x302a/0x3b50
kernel/locking/lockdep.c:3753
Read of size 8 at addr ffff8881cf591a08 by task syz-executor.1/26260

CPU: 1 PID: 26260 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x6a/0x32c mm/kasan/report.c:351
  __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
  kasan_report+0xe/0x12 mm/kasan/common.c:612
  __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753
  lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159
  hiddev_release+0x82/0x520 drivers/hid/usbhid/hiddev.c:221
  __fput+0x2d7/0x840 fs/file_table.c:280
  task_work_run+0x13f/0x1c0 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x8ef/0x2c50 kernel/exit.c:878
  do_group_exit+0x125/0x340 kernel/exit.c:982
  get_signal+0x466/0x23d0 kernel/signal.c:2728
  do_signal+0x88/0x14e0 arch/x86/kernel/signal.c:815
  exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:159
  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
  do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:299
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd b7 fb 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f75b2a6ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000075c078 RCX: 0000000000459829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075c078
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075c07c
R13: 00007ffcdfe1023f R14: 00007f75b2a6d9c0 R15: 000000000075c07c

Allocated by task 104:
  save_stack+0x1b/0x80 mm/kasan/common.c:69
  set_track mm/kasan/common.c:77 [inline]
  __kasan_kmalloc mm/kasan/common.c:487 [inline]
  __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
  kmalloc include/linux/slab.h:552 [inline]
  kzalloc include/linux/slab.h:748 [inline]
  hiddev_connect+0x242/0x5b0 drivers/hid/usbhid/hiddev.c:900
  hid_connect+0x239/0xbb0 drivers/hid/hid-core.c:1882
  hid_hw_start drivers/hid/hid-core.c:1981 [inline]
  hid_hw_start+0xa2/0x130 drivers/hid/hid-core.c:1972
  appleir_probe+0x13e/0x1a0 drivers/hid/hid-appleir.c:308
  hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365
  usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386
  usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
  generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
  usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
  hub_port_connect drivers/usb/core/hub.c:5098 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
  process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
  worker_thread+0x96/0xe20 kernel/workqueue.c:2415
  kthread+0x318/0x420 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 104:
  save_stack+0x1b/0x80 mm/kasan/common.c:69
  set_track mm/kasan/common.c:77 [inline]
  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
  slab_free_hook mm/slub.c:1423 [inline]
  slab_free_freelist_hook mm/slub.c:1470 [inline]
  slab_free mm/slub.c:3012 [inline]
  kfree+0xe4/0x2f0 mm/slub.c:3953
  hiddev_connect.cold+0x45/0x5c drivers/hid/usbhid/hiddev.c:914
  hid_connect+0x239/0xbb0 drivers/hid/hid-core.c:1882
  hid_hw_start drivers/hid/hid-core.c:1981 [inline]
  hid_hw_start+0xa2/0x130 drivers/hid/hid-core.c:1972
  appleir_probe+0x13e/0x1a0 drivers/hid/hid-appleir.c:308
  hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365
  usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386
  usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
  generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
  usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
  really_probe+0x281/0x650 drivers/base/dd.c:548
  driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:882
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2114
  usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
  hub_port_connect drivers/usb/core/hub.c:5098 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
  process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
  worker_thread+0x96/0xe20 kernel/workqueue.c:2415
  kthread+0x318/0x420 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881cf591900
  which belongs to the cache kmalloc-512 of size 512
The buggy address is located 264 bytes inside of
  512-byte region [ffff8881cf591900, ffff8881cf591b00)
The buggy address belongs to the page:
page:ffffea00073d6400 refcount:1 mapcount:0 mapping:ffff8881da002500
index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da002500
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881cf591900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881cf591980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8881cf591a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                       ^
  ffff8881cf591a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881cf591b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

In order to avoid opening a disconnected device, we need to check exist
again after acquiring the existance lock, and bail out if necessary.

Reported-by: default avatarsyzbot <syzbot+62a1e04fd3ec2abf099e@syzkaller.appspotmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarHillf Danton <hdanton@sina.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f95f2186
    • Hillf Danton's avatar
      HID: hiddev: do cleanup in failure of opening a device · e64358af
      Hillf Danton authored 
      
commit 6d4472d7 upstream.

Undo what we did for opening before releasing the memory slice.

Reported-by: default avatarsyzbot <syzbot+62a1e04fd3ec2abf099e@syzkaller.appspotmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarHillf Danton <hdanton@sina.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e64358af
  19. Dec 14, 2019
  21. Dec 02, 2019
    • Mark Salyzyn's avatar
      ANDROID: fiq_debugger: remove · 5066c252
      Mark Salyzyn authored 
      
This represents a rollup of a series of reverts, simplified are
modifications to remove fiq_glue and fiq_debugger references in:

arch/arm/common/Kconfig
arch/arm/common/Makefile
drivers/staging/android/Kconfig
drivers/staging/android/Makefile

And deletion of:

arch/arm/common/fiq_glue.S
arch/arm/common/fiq_glue_setup.c
drivers/staging/android/fiq_debugger/

The reverts specific to android-4.14 are as follows:

Revert "ANDROID: fiq_debugger: Remove wakelock.h dependencies"
This reverts commit f9cbd12e.

Revert "ANDROID: fiq_debugger: Add fiq_debugger.disable option"
This reverts commit 76d292f9.

Revert "ANDROID: fiq_debugger: Add option to apply uart overlay by
        FIQ_DEBUGGER_UART_OVERLAY"
This reverts commit 0ff9e291.

Revert "ANDROID: fiq_debugger: Add fiq_watchdog_triggered api"
This reverts commit 9c027e6c.

Revert "ANDROID: fiq_debugger: Call fiq_debugger_printf through a
        function pointer from cpu specific code"
This reverts commit 9200a45d.

Revert "ANDROID: fiq_debugger: add ARM64 support"
This reverts commit c9d6bc7a.

Revert "ANDROID: fiq_debugger: split arm support into fiq_debugger_arm.c"
This reverts commit efffceb1.

Revert "ANDROID: fiq_debugger: use pt_regs for registers"
This reverts commit bf32f8ac.

Revert "ANDROID: fiq_debugger: allow compiling without CONFIG_FIQ_GLUE"
This reverts commit 16c32489.

Revert "ANDROID: fiq_debugger: rename debug->fiq_debugger"
This reverts commit d241f1df.

Revert "ANDROID: fiq_debugger: move into
        drivers/staging/android/fiq_debugger/"
This reverts commit 0dc1cccb.

Revert "ANDROID: ARM: fiq_debugger: Update tty code for 3.9"
This reverts commit 4b55137d.

Revert "ANDROID: ARM: fiq_debugger: lock between tty and console writes"
This reverts commit a8be4623.

Revert "ANDROID: ARM: fiq_debugger: add process context reboot command"
This reverts commit cb5774b5.

Revert "ANDROID: ARM: fiq_debugger: fix multiple consoles and make it
        a preferred console"
This reverts commit aecfa53f.

Revert "ANDROID: ARM: fiq_debugger: add support for kgdb"
This reverts commit 992dbb2a.

Revert "ANDROID: ARM: fiq_debugger: add debug_putc"
This reverts commit 5d12c56f.

Revert "ANDROID: ARM: fiq_debugger: add support for reboot commands"
This reverts commit 14dbf867.

Revert "ANDROID: ARM: fiq_debugger: Add generic fiq serial debugger"
This reverts commit 05e1c7f6.

Revert "ANDROID: ARM: fiq_glue: Add custom fiq return handler api."
This reverts commit e329aaf3.

Revert "ANDROID: ARM: fiq_glue: Add fiq_glue"
This reverts commit 47fe2f8d.

Signed-off-by: default avatarMark Salyzyn <salyzyn@google.com>
Bug: 32402555
Bug: 36101220
Change-Id: I3f74b1ff5e4971d619bcb37a911fed68fbb538d5
      ASB-2019-12-05_4.14-p-release
      5066c252
    • Alan Stern's avatar
      p54usb: Fix race between disconnect and firmware loading · a0c1e370
      Alan Stern authored 
      
commit 6e41e225 upstream.

The syzbot fuzzer found a bug in the p54 USB wireless driver.  The
issue involves a race between disconnect and the firmware-loader
callback routine, and it has several aspects.

One big problem is that when the firmware can't be loaded, the
callback routine tries to unbind the driver from the USB _device_ (by
calling device_release_driver) instead of from the USB _interface_ to
which it is actually bound (by calling usb_driver_release_interface).

The race involves access to the private data structure.  The driver's
disconnect handler waits for a completion that is signalled by the
firmware-loader callback routine.  As soon as the completion is
signalled, you have to assume that the private data structure may have
been deallocated by the disconnect handler -- even if the firmware was
loaded without errors.  However, the callback routine does access the
private data several times after that point.

Another problem is that, in order to ensure that the USB device
structure hasn't been freed when the callback routine runs, the driver
takes a reference to it.  This isn't good enough any more, because now
that the callback routine calls usb_driver_release_interface, it has
to ensure that the interface structure hasn't been freed.

Finally, the driver takes an unnecessary reference to the USB device
structure in the probe function and drops the reference in the
disconnect handler.  This extra reference doesn't accomplish anything,
because the USB core already guarantees that a device structure won't
be deallocated while a driver is still bound to any of its interfaces.

To fix these problems, this patch makes the following changes:

	Call usb_driver_release_interface() rather than
	device_release_driver().

	Don't signal the completion until after the important
	information has been copied out of the private data structure,
	and don't refer to the private data at all thereafter.

	Lock udev (the interface's parent) before unbinding the driver
	instead of locking udev->parent.

	During the firmware loading process, take a reference to the
	USB interface instead of the USB device.

	Don't take an unnecessary reference to the device during probe
	(and then don't drop it during disconnect).

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: default avatar <syzbot+200d4bb11b23d929335f@syzkaller.appspotmail.com>
CC: <stable@vger.kernel.org>
Acked-by: default avatarChristian Lamparter <chunkeey@gmail.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a0c1e370
  23. Nov 04, 2019
  25. Oct 04, 2019
  27. Jun 12, 2019
  29. May 31, 2019