diff options
| author | Elliot Berman <quic_eberman@quicinc.com> | 2021-08-11 08:59:14 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-08-11 13:11:12 -0700 |
| commit | 14c4c8e41511aa8fba7fb239b20b6539b5bce201 (patch) | |
| tree | 44d64cc2aaaaa805627fee8d6433a7efff58f6c4 /net/dns_resolver | |
| parent | 36a21d51725af2ce0700c6ebcb6b9594aac658a6 (diff) | |
cfi: Use rcu_read_{un}lock_sched_notrace
If rcu_read_lock_sched tracing is enabled, the tracing subsystem can
perform a jump which needs to be checked by CFI. For example, stm_ftrace
source is enabled as a module and hooks into enabled ftrace events. This
can cause an recursive loop where find_shadow_check_fn ->
rcu_read_lock_sched -> (call to stm_ftrace generates cfi slowpath) ->
find_shadow_check_fn -> rcu_read_lock_sched -> ...
To avoid the recursion, either the ftrace codes needs to be marked with
__no_cfi or CFI should not trace. Use the "_notrace" in CFI to avoid
tracing so that CFI can guard ftrace.
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Cc: stable@vger.kernel.org
Fixes: cf68fffb66d6 ("add support for Clang CFI")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210811155914.19550-1-quic_eberman@quicinc.com
Diffstat (limited to 'net/dns_resolver')
0 files changed, 0 insertions, 0 deletions