| Message ID | 20211008065830.305057-1-butterflyhuangxx@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1f3e2e97c003f80c4b087092b225c8787ff91e4d |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | isdn: cpai: check ctr->cnr to avoid array index out of bound | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Fri, Oct 8, 2021 at 8:58 AM Xiaolong Huang <butterflyhuangxx@gmail.com> wrote: > > The cmtp_add_connection() would add a cmtp session to a controller > and run a kernel thread to process cmtp. > > __module_get(THIS_MODULE); > session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d", > session->num); > > During this process, the kernel thread would call detach_capi_ctr() > to detach a register controller. if the controller > was not attached yet, detach_capi_ctr() would > trigger an array-index-out-bounds bug. > > [ 46.866069][ T6479] UBSAN: array-index-out-of-bounds in > drivers/isdn/capi/kcapi.c:483:21 > [ 46.867196][ T6479] index -1 is out of range for type 'capi_ctr *[32]' > [ 46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpd_ctr_0 Not tainted > 5.15.0-rc2+ #8 > [ 46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX, > 1996), BIOS 1.14.0-2 04/01/2014 > [ 46.870107][ T6479] Call Trace: > [ 46.870473][ T6479] dump_stack_lvl+0x57/0x7d > [ 46.870974][ T6479] ubsan_epilogue+0x5/0x40 > [ 46.871458][ T6479] __ubsan_handle_out_of_bounds.cold+0x43/0x48 > [ 46.872135][ T6479] detach_capi_ctr+0x64/0xc0 > [ 46.872639][ T6479] cmtp_session+0x5c8/0x5d0 > [ 46.873131][ T6479] ? __init_waitqueue_head+0x60/0x60 > [ 46.873712][ T6479] ? cmtp_add_msgpart+0x120/0x120 > [ 46.874256][ T6479] kthread+0x147/0x170 > [ 46.874709][ T6479] ? set_kthread_struct+0x40/0x40 > [ 46.875248][ T6479] ret_from_fork+0x1f/0x30 > [ 46.875773][ T6479] > > Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski <kuba@kernel.org>: On Fri, 8 Oct 2021 14:58:30 +0800 you wrote: > The cmtp_add_connection() would add a cmtp session to a controller > and run a kernel thread to process cmtp. > > __module_get(THIS_MODULE); > session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d", > session->num); > > [...] Here is the summary with links: - isdn: cpai: check ctr->cnr to avoid array index out of bound https://git.kernel.org/netdev/net/c/1f3e2e97c003 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c index cb0afe897162..7313454e403a 100644 --- a/drivers/isdn/capi/kcapi.c +++ b/drivers/isdn/capi/kcapi.c @@ -480,6 +480,11 @@ int detach_capi_ctr(struct capi_ctr *ctr) ctr_down(ctr, CAPI_CTR_DETACHED); + if (ctr->cnr < 1 || ctr->cnr - 1 >= CAPI_MAXCONTR) { + err = -EINVAL; + goto unlock_out; + } + if (capi_controller[ctr->cnr - 1] != ctr) { err = -EINVAL; goto unlock_out;
The cmtp_add_connection() would add a cmtp session to a controller and run a kernel thread to process cmtp. __module_get(THIS_MODULE); session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d", session->num); During this process, the kernel thread would call detach_capi_ctr() to detach a register controller. if the controller was not attached yet, detach_capi_ctr() would trigger an array-index-out-bounds bug. [ 46.866069][ T6479] UBSAN: array-index-out-of-bounds in drivers/isdn/capi/kcapi.c:483:21 [ 46.867196][ T6479] index -1 is out of range for type 'capi_ctr *[32]' [ 46.867982][ T6479] CPU: 1 PID: 6479 Comm: kcmtpd_ctr_0 Not tainted 5.15.0-rc2+ #8 [ 46.869002][ T6479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 46.870107][ T6479] Call Trace: [ 46.870473][ T6479] dump_stack_lvl+0x57/0x7d [ 46.870974][ T6479] ubsan_epilogue+0x5/0x40 [ 46.871458][ T6479] __ubsan_handle_out_of_bounds.cold+0x43/0x48 [ 46.872135][ T6479] detach_capi_ctr+0x64/0xc0 [ 46.872639][ T6479] cmtp_session+0x5c8/0x5d0 [ 46.873131][ T6479] ? __init_waitqueue_head+0x60/0x60 [ 46.873712][ T6479] ? cmtp_add_msgpart+0x120/0x120 [ 46.874256][ T6479] kthread+0x147/0x170 [ 46.874709][ T6479] ? set_kthread_struct+0x40/0x40 [ 46.875248][ T6479] ret_from_fork+0x1f/0x30 [ 46.875773][ T6479] Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com> --- drivers/isdn/capi/kcapi.c | 5 +++++ 1 file changed, 5 insertions(+)