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author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2020-07-29 23:57:01 +0900 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-18 13:18:17 +0200 |
commit | f8d1653daec02315e06d30246cff4af72e76e54e (patch) | |
tree | a7804e5ed72e52c54f9f0a8c38779919d79952ef /tools/perf/scripts/python/export-to-postgresql.py | |
parent | 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5 (diff) |
vt: defer kfree() of vc_screenbuf in vc_do_resize()
syzbot is reporting UAF bug in set_origin() from vc_do_resize() [1], for
vc_do_resize() calls kfree(vc->vc_screenbuf) before calling set_origin().
Unfortunately, in set_origin(), vc->vc_sw->con_set_origin() might access
vc->vc_pos when scroll is involved in order to manipulate cursor, but
vc->vc_pos refers already released vc->vc_screenbuf until vc->vc_pos gets
updated based on the result of vc->vc_sw->con_set_origin().
Preserving old buffer and tolerating outdated vc members until set_origin()
completes would be easier than preventing vc->vc_sw->con_set_origin() from
accessing outdated vc members.
[1] https://syzkaller.appspot.com/bug?id=6649da2081e2ebdc65c0642c214b27fe91099db3
Reported-by: syzbot <syzbot+9116ecc1978ca3a12f43@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1596034621-4714-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions