| Message ID | 20231108154420.1474853-1-syoshida@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 719639853d88071dfdfd8d9971eca9c283ff314c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] tty: Fix uninit-value access in ppp_sync_receive() | expand |
On Thu, Nov 09, 2023 at 12:44:20AM +0900, Shigeru Yoshida wrote: > KMSAN reported the following uninit-value access issue: > > ===================================================== > BUG: KMSAN: uninit-value in ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] > BUG: KMSAN: uninit-value in ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 > ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] > ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 > tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 > tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 > __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:51 [inline] > do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > Uninit was created at: > __alloc_pages+0x75d/0xe80 mm/page_alloc.c:4591 > __alloc_pages_node include/linux/gfp.h:238 [inline] > alloc_pages_node include/linux/gfp.h:261 [inline] > __page_frag_cache_refill+0x9a/0x2c0 mm/page_alloc.c:4691 > page_frag_alloc_align+0x91/0x5d0 mm/page_alloc.c:4722 > page_frag_alloc include/linux/gfp.h:322 [inline] > __netdev_alloc_skb+0x215/0x6d0 net/core/skbuff.c:728 > netdev_alloc_skb include/linux/skbuff.h:3225 [inline] > dev_alloc_skb include/linux/skbuff.h:3238 [inline] > ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline] > ppp_sync_receive+0x237/0xe70 drivers/net/ppp/ppp_synctty.c:334 > tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 > tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 > __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:51 [inline] > do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > CPU: 0 PID: 12950 Comm: syz-executor.1 Not tainted 6.6.0-14500-g1c41041124bd #10 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 > ===================================================== > > ppp_sync_input() checks the first 2 bytes of the data are PPP_ALLSTATIONS > and PPP_UI. However, if the data length is 1 and the first byte is > PPP_ALLSTATIONS, an access to an uninitialized value occurs when checking > PPP_UI. This patch resolves this issue by checking the data length. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org>
Hello: This patch was applied to netdev/net.git (main) by David S. Miller <davem@davemloft.net>: On Thu, 9 Nov 2023 00:44:20 +0900 you wrote: > KMSAN reported the following uninit-value access issue: > > ===================================================== > BUG: KMSAN: uninit-value in ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] > BUG: KMSAN: uninit-value in ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 > ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] > ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 > tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 > tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 > __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:51 [inline] > do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 > entry_SYSCALL_64_after_hwframe+0x63/0x6b > > [...] Here is the summary with links: - [net] tty: Fix uninit-value access in ppp_sync_receive() https://git.kernel.org/netdev/net/c/719639853d88 You are awesome, thank you!
diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c index ebcdffdf4f0e..ea261a628786 100644 --- a/drivers/net/ppp/ppp_synctty.c +++ b/drivers/net/ppp/ppp_synctty.c @@ -687,7 +687,7 @@ ppp_sync_input(struct syncppp *ap, const u8 *buf, const u8 *flags, int count) /* strip address/control field if present */ p = skb->data; - if (p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) { + if (skb->len >= 2 && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) { /* chop off address/control */ if (skb->len < 3) goto err;
KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] BUG: KMSAN: uninit-value in ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 ppp_sync_input drivers/net/ppp/ppp_synctty.c:690 [inline] ppp_sync_receive+0xdc9/0xe70 drivers/net/ppp/ppp_synctty.c:334 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: __alloc_pages+0x75d/0xe80 mm/page_alloc.c:4591 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __page_frag_cache_refill+0x9a/0x2c0 mm/page_alloc.c:4691 page_frag_alloc_align+0x91/0x5d0 mm/page_alloc.c:4722 page_frag_alloc include/linux/gfp.h:322 [inline] __netdev_alloc_skb+0x215/0x6d0 net/core/skbuff.c:728 netdev_alloc_skb include/linux/skbuff.h:3225 [inline] dev_alloc_skb include/linux/skbuff.h:3238 [inline] ppp_sync_input drivers/net/ppp/ppp_synctty.c:669 [inline] ppp_sync_receive+0x237/0xe70 drivers/net/ppp/ppp_synctty.c:334 tiocsti+0x328/0x450 drivers/tty/tty_io.c:2295 tty_ioctl+0x808/0x1920 drivers/tty/tty_io.c:2694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0x211/0x400 fs/ioctl.c:857 __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 12950 Comm: syz-executor.1 Not tainted 6.6.0-14500-g1c41041124bd #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 ===================================================== ppp_sync_input() checks the first 2 bytes of the data are PPP_ALLSTATIONS and PPP_UI. However, if the data length is 1 and the first byte is PPP_ALLSTATIONS, an access to an uninitialized value occurs when checking PPP_UI. This patch resolves this issue by checking the data length. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> --- drivers/net/ppp/ppp_synctty.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)