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| author | Zhengjun Xing <zhengjun.xing@linux.intel.com> | 2018-02-12 15:24:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-15 20:36:19 +0300 |
| commit | fa2dfd0ec22e0069c84dfae162972cbbc7c75488 (patch) | |
| tree | 489edaf8e409e0cd53e95b30d1299b03af72f2e1 /drivers | |
| parent | 1208d8a84fdcae6b395c57911cdf907450d30e70 (diff) | |
| download | linux-fa2dfd0ec22e0069c84dfae162972cbbc7c75488.tar.xz | |
xhci: Fix NULL pointer in xhci debugfs
Commit dde634057da7 ("xhci: Fix use-after-free in xhci debugfs") causes a
null pointer dereference while fixing xhci-debugfs usage of ring pointers
that were freed during hibernate.
The fix passed addresses to ring pointers instead, but forgot to do this
change for the xhci_ring_trb_show function.
The address of the ring pointer passed to xhci-debugfs was of a temporary
ring pointer "new_ring" instead of the actual ring "ring" pointer. The
temporary new_ring pointer will be set to NULL later causing the NULL
pointer dereference.
This issue was seen when reading xhci related files in debugfs:
cat /sys/kernel/debug/usb/xhci/*/devices/*/ep*/trbs
[ 184.604861] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 184.613776] IP: xhci_ring_trb_show+0x3a/0x890
[ 184.618733] PGD 264193067 P4D 264193067 PUD 263238067 PMD 0
[ 184.625184] Oops: 0000 [#1] SMP
[ 184.726410] RIP: 0010:xhci_ring_trb_show+0x3a/0x890
[ 184.731944] RSP: 0018:ffffba8243c0fd90 EFLAGS: 00010246
[ 184.737880] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000295d6
[ 184.746020] RDX: 00000000000295d5 RSI: 0000000000000001 RDI: ffff971a6418d400
[ 184.754121] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[ 184.762222] R10: ffff971a64c98a80 R11: ffff971a62a00e40 R12: ffff971a62a85500
[ 184.770325] R13: 0000000000020000 R14: ffff971a6418d400 R15: ffff971a6418d400
[ 184.778448] FS: 00007fe725a79700(0000) GS:ffff971a6ec00000(0000) knlGS:0000000000000000
[ 184.787644] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 184.794168] CR2: 0000000000000000 CR3: 000000025f365005 CR4: 00000000003606f0
[ 184.802318] Call Trace:
[ 184.805094] ? seq_read+0x281/0x3b0
[ 184.809068] seq_read+0xeb/0x3b0
[ 184.812735] full_proxy_read+0x4d/0x70
[ 184.817007] __vfs_read+0x23/0x120
[ 184.820870] vfs_read+0x91/0x130
[ 184.824538] SyS_read+0x42/0x90
[ 184.828106] entry_SYSCALL_64_fastpath+0x1a/0x7d
Fixes: dde634057da7 ("xhci: Fix use-after-free in xhci debugfs")
Cc: <stable@vger.kernel.org> # v4.15
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/xhci-debugfs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c index e26e685d8a57..5851052d4668 100644 --- a/drivers/usb/host/xhci-debugfs.c +++ b/drivers/usb/host/xhci-debugfs.c @@ -211,7 +211,7 @@ static void xhci_ring_dump_segment(struct seq_file *s, static int xhci_ring_trb_show(struct seq_file *s, void *unused) { int i; - struct xhci_ring *ring = s->private; + struct xhci_ring *ring = *(struct xhci_ring **)s->private; struct xhci_segment *seg = ring->first_seg; for (i = 0; i < ring->num_segs; i++) { @@ -387,7 +387,7 @@ void xhci_debugfs_create_endpoint(struct xhci_hcd *xhci, snprintf(epriv->name, sizeof(epriv->name), "ep%02d", ep_index); epriv->root = xhci_debugfs_create_ring_dir(xhci, - &dev->eps[ep_index].new_ring, + &dev->eps[ep_index].ring, epriv->name, spriv->root); spriv->eps[ep_index] = epriv; |