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| author |   Grzegorz Halat <ghalat@redhat.com> | 2019-04-26 16:59:46 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-24 17:08:18 +0200 |
| commit | a1ad1cc9704f64c169261a76e1aee1cf1ae51832 (patch) | |
| tree | 68930207b4e0231d10ae0fbfe8b3d512f8ae1ac2 /drivers/video | |
| parent | tty: max310x: Fix external crystal register setup (diff) | |
| download | linux-dev-a1ad1cc9704f64c169261a76e1aee1cf1ae51832.tar.xz linux-dev-a1ad1cc9704f64c169261a76e1aee1cf1ae51832.zip | |
vt/fbcon: deinitialize resources in visual_init() after failed memory allocation
After memory allocation failure vc_allocate() doesn't clean up data
which has been initialized in visual_init(). In case of fbcon this
leads to divide-by-0 in fbcon_init() on next open of the same tty.
memory allocation in vc_allocate() may fail here:
1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
on next open() fbcon_init() skips vc_font.data initialization:
1088: if (!p->fontdata) {
division by zero in fbcon_init() happens here:
1149: new_cols /= vc->vc_font.width;
Additional check is needed in fbcon_deinit() to prevent
usage of uninitialized vc_screenbuf:
1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf)
1252: set_vc_hi_font(vc, false);
Crash:
#6 [ffffc90001eafa60] divide_error at ffffffff81a00be4
[exception RIP: fbcon_init+463]
RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246
...
#7 [ffffc90001eafb60] visual_init at ffffffff8154c36e
#8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c
#9 [ffffc90001eafbc8] con_install at ffffffff8154f624
...
Signed-off-by: Grzegorz Halat <ghalat@redhat.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/core/fbcon.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 786f9aab55df..a9c69ae30878 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -1248,7 +1248,7 @@ finished: if (free_font) vc->vc_font.data = NULL; - if (vc->vc_hi_font_mask) + if (vc->vc_hi_font_mask && vc->vc_screenbuf) set_vc_hi_font(vc, false); if (!con_is_bound(&fb_con)) |