| Message ID | 20221207093924.v2.1.I1864b6a7ee98824118b93677868d22d3750f439b@changeid (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9a8aadcf0b459c1257b9477fd6402e1d5952ae07 |
| Headers | show |
| Series | [v2] platform/chrome: cros_ec_typec: zero out stale pointers | expand |
On Dec 07 09:39, Victor Ding wrote: > `cros_typec_get_switch_handles` allocates four pointers when obtaining > type-c switch handles. These pointers are all freed if failing to obtain > any of them; therefore, pointers in `port` become stale. The stale > pointers eventually cause use-after-free or double free in later code > paths. Zeroing out all pointer fields after freeing to eliminate these > stale pointers. > > Fixes: f28adb41dab4 ("platform/chrome: cros_ec_typec: Register Type C switches") > Fixes: 1a8912caba02 ("platform/chrome: cros_ec_typec: Get retimer handle") > Signed-off-by: Victor Ding <victording@chromium.org> Acked-by: Prashant Malani <pmalani@chromium.org> Hey Tzung-Bi, it looks like you've already created a tag for the v6.2 pull request, so I don't know if it's too late to apply this for the current dev cycle. So, I've not applied it, but have left the Acked-by tag. Please feel free to apply it if there's still room for it before you send out the pull request. Thanks!
Hello: This patch was applied to chrome-platform/linux.git (for-kernelci) by Tzung-Bi Shih <tzungbi@kernel.org>: On Wed, 7 Dec 2022 09:39:40 +0000 you wrote: > `cros_typec_get_switch_handles` allocates four pointers when obtaining > type-c switch handles. These pointers are all freed if failing to obtain > any of them; therefore, pointers in `port` become stale. The stale > pointers eventually cause use-after-free or double free in later code > paths. Zeroing out all pointer fields after freeing to eliminate these > stale pointers. > > [...] Here is the summary with links: - [v2] platform/chrome: cros_ec_typec: zero out stale pointers https://git.kernel.org/chrome-platform/c/9a8aadcf0b45 You are awesome, thank you!
Hello: This patch was applied to chrome-platform/linux.git (for-next) by Tzung-Bi Shih <tzungbi@kernel.org>: On Wed, 7 Dec 2022 09:39:40 +0000 you wrote: > `cros_typec_get_switch_handles` allocates four pointers when obtaining > type-c switch handles. These pointers are all freed if failing to obtain > any of them; therefore, pointers in `port` become stale. The stale > pointers eventually cause use-after-free or double free in later code > paths. Zeroing out all pointer fields after freeing to eliminate these > stale pointers. > > [...] Here is the summary with links: - [v2] platform/chrome: cros_ec_typec: zero out stale pointers https://git.kernel.org/chrome-platform/c/9a8aadcf0b45 You are awesome, thank you!
On Wed, Dec 07, 2022 at 10:54:17PM +0000, Prashant Malani wrote: > On Dec 07 09:39, Victor Ding wrote: > > `cros_typec_get_switch_handles` allocates four pointers when obtaining > > type-c switch handles. These pointers are all freed if failing to obtain > > any of them; therefore, pointers in `port` become stale. The stale > > pointers eventually cause use-after-free or double free in later code > > paths. Zeroing out all pointer fields after freeing to eliminate these > > stale pointers. > > > > Fixes: f28adb41dab4 ("platform/chrome: cros_ec_typec: Register Type C switches") > > Fixes: 1a8912caba02 ("platform/chrome: cros_ec_typec: Get retimer handle") > > Signed-off-by: Victor Ding <victording@chromium.org> > Acked-by: Prashant Malani <pmalani@chromium.org> > > Hey Tzung-Bi, it looks like you've already created a tag for the > v6.2 pull request, so I don't know if it's too late to apply this > for the current dev cycle. > So, I've not applied it, but have left the Acked-by tag. > > Please feel free to apply it if there's still room for it before > you send out the pull request. Given that the patch fixes an use-after-free, let's include this in the coming merge window. Have queued.
diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c index 2a7ff14dc37e..59de4ce01fab 100644 --- a/drivers/platform/chrome/cros_ec_typec.c +++ b/drivers/platform/chrome/cros_ec_typec.c @@ -173,10 +173,13 @@ static int cros_typec_get_switch_handles(struct cros_typec_port *port, role_sw_err: typec_switch_put(port->ori_sw); + port->ori_sw = NULL; ori_sw_err: typec_retimer_put(port->retimer); + port->retimer = NULL; retimer_sw_err: typec_mux_put(port->mux); + port->mux = NULL; mux_err: return -ENODEV; }
`cros_typec_get_switch_handles` allocates four pointers when obtaining type-c switch handles. These pointers are all freed if failing to obtain any of them; therefore, pointers in `port` become stale. The stale pointers eventually cause use-after-free or double free in later code paths. Zeroing out all pointer fields after freeing to eliminate these stale pointers. Fixes: f28adb41dab4 ("platform/chrome: cros_ec_typec: Register Type C switches") Fixes: 1a8912caba02 ("platform/chrome: cros_ec_typec: Get retimer handle") Signed-off-by: Victor Ding <victording@chromium.org> --- Changes in v2: - Updated commit messages; - No code changes. drivers/platform/chrome/cros_ec_typec.c | 3 +++ 1 file changed, 3 insertions(+)