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comparison always true #240

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eyedeeemm opened this issue Oct 11, 2016 · 0 comments
Open

comparison always true #240

eyedeeemm opened this issue Oct 11, 2016 · 0 comments

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@eyedeeemm
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(in odroid-c1 kernel)

drivers/amlogic/amports/amvdec.c" line 827
(rp == old_rp && wp == old_wp && level == level)) { /no write && not read/

should perhaps say "level == old_level" ?

mdrjr pushed a commit that referenced this issue Mar 21, 2019
[ Upstream commit afc9f65 ]

When building the kernel as Thumb-2 with binutils 2.29 or newer, if the
assembler has seen the .type directive (via ENDPROC()) for a symbol, it
automatically handles the setting of the lowest bit when the symbol is
used with ADR.  The badr macro on the other hand handles this lowest bit
manually.  This leads to a jump to a wrong address in the wrong state
in the syscall return path:

 Internal error: Oops - undefined instruction: 0 [#2] SMP THUMB2
 Modules linked in:
 CPU: 0 PID: 652 Comm: modprobe Tainted: G      D           4.18.0-rc3+ #8
 PC is at ret_fast_syscall+0x4/0x62
 LR is at sys_brk+0x109/0x128
 pc : [<80101004>]    lr : [<801c8a35>]    psr: 60000013
 Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
 Control: 50c5387d  Table: 9e82006a  DAC: 00000051
 Process modprobe (pid: 652, stack limit = 0x(ptrval))

 80101000 <ret_fast_syscall>:
 80101000:       b672            cpsid   i
 80101002:       f8d9 2008       ldr.w   r2, [r9, #8]
 80101006:       f1b2 4ffe       cmp.w   r2, #2130706432 ; 0x7f000000

 80101184 <local_restart>:
 80101184:       f8d9 a000       ldr.w   sl, [r9]
 80101188:       e92d 0030       stmdb   sp!, {r4, r5}
 8010118c:       f01a 0ff0       tst.w   sl, #240        ; 0xf0
 80101190:       d117            bne.n   801011c2 <__sys_trace>
 80101192:       46ba            mov     sl, r7
 80101194:       f5ba 7fc8       cmp.w   sl, #400        ; 0x190
 80101198:       bf28            it      cs
 8010119a:       f04f 0a00       movcs.w sl, #0
 8010119e:       f3af 8014       nop.w   {20}
 801011a2:       f2af 1ea2       subw    lr, pc, #418    ; 0x1a2

To fix this, add a new symbol name which doesn't have ENDPROC used on it
and use that with badr.  We can't remove the badr usage since that would
would cause breakage with older binutils.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mdrjr pushed a commit that referenced this issue Apr 16, 2019
[ Upstream commit afc9f65 ]

When building the kernel as Thumb-2 with binutils 2.29 or newer, if the
assembler has seen the .type directive (via ENDPROC()) for a symbol, it
automatically handles the setting of the lowest bit when the symbol is
used with ADR.  The badr macro on the other hand handles this lowest bit
manually.  This leads to a jump to a wrong address in the wrong state
in the syscall return path:

 Internal error: Oops - undefined instruction: 0 [#2] SMP THUMB2
 Modules linked in:
 CPU: 0 PID: 652 Comm: modprobe Tainted: G      D           4.18.0-rc3+ #8
 PC is at ret_fast_syscall+0x4/0x62
 LR is at sys_brk+0x109/0x128
 pc : [<80101004>]    lr : [<801c8a35>]    psr: 60000013
 Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
 Control: 50c5387d  Table: 9e82006a  DAC: 00000051
 Process modprobe (pid: 652, stack limit = 0x(ptrval))

 80101000 <ret_fast_syscall>:
 80101000:       b672            cpsid   i
 80101002:       f8d9 2008       ldr.w   r2, [r9, #8]
 80101006:       f1b2 4ffe       cmp.w   r2, #2130706432 ; 0x7f000000

 80101184 <local_restart>:
 80101184:       f8d9 a000       ldr.w   sl, [r9]
 80101188:       e92d 0030       stmdb   sp!, {r4, r5}
 8010118c:       f01a 0ff0       tst.w   sl, #240        ; 0xf0
 80101190:       d117            bne.n   801011c2 <__sys_trace>
 80101192:       46ba            mov     sl, r7
 80101194:       f5ba 7fc8       cmp.w   sl, #400        ; 0x190
 80101198:       bf28            it      cs
 8010119a:       f04f 0a00       movcs.w sl, #0
 8010119e:       f3af 8014       nop.w   {20}
 801011a2:       f2af 1ea2       subw    lr, pc, #418    ; 0x1a2

To fix this, add a new symbol name which doesn't have ENDPROC used on it
and use that with badr.  We can't remove the badr usage since that would
would cause breakage with older binutils.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mdrjr pushed a commit that referenced this issue Jul 16, 2019
[ Upstream commit 309b669 ]

In order to create an internal vport, internal_dev_create() is used and
that calls register_netdevice() internally.
If register_netdevice() fails, it calls dev->priv_destructor() to free
private data of netdev. actually, a private data of this is a vport.

Hence internal_dev_create() should not free and use a vport after failure
of register_netdevice().

Test command
    ovs-dpctl add-dp bonding_masters

Splat looks like:
[ 1035.667767] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 1035.675958] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1035.676916] CPU: 1 PID: 1028 Comm: ovs-vswitchd Tainted: G    B             5.2.0-rc3+ #240
[ 1035.676916] RIP: 0010:internal_dev_create+0x2e5/0x4e0 [openvswitch]
[ 1035.676916] Code: 48 c1 ea 03 80 3c 02 00 0f 85 9f 01 00 00 4c 8b 23 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 60 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 86 01 00 00 49 8b bc 24 60 05 00 00 e8 e4 68 f4
[ 1035.713720] RSP: 0018:ffff88810dcb7578 EFLAGS: 00010206
[ 1035.713720] RAX: dffffc0000000000 RBX: ffff88810d13fe08 RCX: ffffffff84297704
[ 1035.713720] RDX: 00000000000000ac RSI: 0000000000000000 RDI: 0000000000000560
[ 1035.713720] RBP: 00000000ffffffef R08: fffffbfff0d3b881 R09: fffffbfff0d3b881
[ 1035.713720] R10: 0000000000000001 R11: fffffbfff0d3b880 R12: 0000000000000000
[ 1035.768776] R13: 0000607ee460b900 R14: ffff88810dcb7690 R15: ffff88810dcb7698
[ 1035.777709] FS:  00007f02095fc980(0000) GS:ffff88811b400000(0000) knlGS:0000000000000000
[ 1035.777709] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1035.777709] CR2: 00007ffdf01d2f28 CR3: 0000000108258000 CR4: 00000000001006e0
[ 1035.777709] Call Trace:
[ 1035.777709]  ovs_vport_add+0x267/0x4f0 [openvswitch]
[ 1035.777709]  new_vport+0x15/0x1e0 [openvswitch]
[ 1035.777709]  ovs_vport_cmd_new+0x567/0xd10 [openvswitch]
[ 1035.777709]  ? ovs_dp_cmd_dump+0x490/0x490 [openvswitch]
[ 1035.777709]  ? __kmalloc+0x131/0x2e0
[ 1035.777709]  ? genl_family_rcv_msg+0xa54/0x1030
[ 1035.777709]  genl_family_rcv_msg+0x63a/0x1030
[ 1035.777709]  ? genl_unregister_family+0x630/0x630
[ 1035.841681]  ? debug_show_all_locks+0x2d0/0x2d0
[ ... ]

Fixes: cf124db ("net: Fix inconsistent teardown and release of private netdev state.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ardje pushed a commit to ardje/linux that referenced this issue Feb 5, 2020
commit 04b6942 upstream.

hsr slave interfaces don't have debugfs directory.
So, hsr_debugfs_rename() shouldn't be called when hsr slave interface name
is changed.

Test commands:
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1
    ip link set dummy0 name ap

Splat looks like:
[21071.899367][T22666] ap: renamed from dummy0
[21071.914005][T22666] ==================================================================
[21071.919008][T22666] BUG: KASAN: slab-out-of-bounds in hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.923640][T22666] Read of size 8 at addr ffff88805febcd98 by task ip/22666
[21071.926941][T22666]
[21071.927750][T22666] CPU: 0 PID: 22666 Comm: ip Not tainted 5.5.0-rc2+ hardkernel#240
[21071.929919][T22666] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[21071.935094][T22666] Call Trace:
[21071.935867][T22666]  dump_stack+0x96/0xdb
[21071.936687][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.937774][T22666]  print_address_description.constprop.5+0x1be/0x360
[21071.939019][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.940081][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.940949][T22666]  __kasan_report+0x12a/0x16f
[21071.941758][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.942674][T22666]  kasan_report+0xe/0x20
[21071.943325][T22666]  hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.944187][T22666]  hsr_netdev_notify+0x1fe/0x9b0 [hsr]
[21071.945052][T22666]  ? __module_text_address+0x13/0x140
[21071.945897][T22666]  notifier_call_chain+0x90/0x160
[21071.946743][T22666]  dev_change_name+0x419/0x840
[21071.947496][T22666]  ? __read_once_size_nocheck.constprop.6+0x10/0x10
[21071.948600][T22666]  ? netdev_adjacent_rename_links+0x280/0x280
[21071.949577][T22666]  ? __read_once_size_nocheck.constprop.6+0x10/0x10
[21071.950672][T22666]  ? lock_downgrade+0x6e0/0x6e0
[21071.951345][T22666]  ? do_setlink+0x811/0x2ef0
[21071.951991][T22666]  do_setlink+0x811/0x2ef0
[21071.952613][T22666]  ? is_bpf_text_address+0x81/0xe0
[ ... ]

Reported-by: syzbot+9328206518f08318a5fd@syzkaller.appspotmail.com
Fixes: 4c2d5e3 ("hsr: rename debugfs file when interface name is changed")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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