[ Upstream commit d005fbb855d3b5660d62ee5a6bd2d99c13ff8cf3 ] __nf_conntrack_update() might refresh the conntrack object that is attached to the skbuff. Otherwise, this triggers UAF. [ 633.200434] ================================================================== [ 633.200472] BUG: KASAN: use-after-free in nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200478] Read of size 1 at addr ffff888370804c00 by task nfqnl_test/6769 [ 633.200487] CPU: 1 PID: 6769 Comm: nfqnl_test Not tainted 5.8.0-rc2+ #388 [ 633.200490] Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012 [ 633.200491] Call Trace: [ 633.200499] dump_stack+0x7c/0xb0 [ 633.200526] ? nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200532] print_address_description.constprop.6+0x1a/0x200 [ 633.200539] ? _raw_write_lock_irqsave+0xc0/0xc0 [ 633.200568] ? nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200594] ? nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200598] kasan_report.cold.9+0x1f/0x42 [ 633.200604] ? call_rcu+0x2c0/0x390 [ 633.200633] ? nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200659] nf_conntrack_update+0x34e/0x770 [nf_conntrack] [ 633.200687] ? nf_conntrack_find_get+0x30/0x30 [nf_conntrack] Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1436 Fixes: ee04805ff54a ("netfilter: conntrack: make conntrack userspace helpers work again") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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