kernel/linux.git, branch v4.4.297

Linux 4.4.297

2021-12-29T10:50:30+00:00

Link: https://lore.kernel.org/r/20211227151315.962187770@linuxfoundation.org Tested-by: Pavel Machek (CIP) Tested-by: Guenter Roeck Tested-by: Linux Kernel Functional Testing Tested-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

phonet/pep: refuse to enable an unbound pipe

2021-12-29T10:50:30+00:00

commit 75a2f31520095600f650597c0ac41f48b5ba0068 upstream. This ioctl() implicitly assumed that the socket was already bound to a valid local socket name, i.e. Phonet object. If the socket was not bound, two separate problems would occur: 1) We'd send an pipe enablement request with an invalid source object. 2) Later socket calls could BUG on the socket unexpectedly being connected yet not bound to a valid object. Reported-by: syzbot+2dc91e7fc3dea88b1e8a@syzkaller.appspotmail.com Signed-off-by: Rémi Denis-Courmont Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hamradio: improve the incomplete fix to avoid NPD

2021-12-29T10:50:30+00:00

commit b2f37aead1b82a770c48b5d583f35ec22aabb61e upstream. The previous commit 3e0588c291d6 ("hamradio: defer ax25 kfree after unregister_netdev") reorder the kfree operations and unregister_netdev operation to prevent UAF. This commit improves the previous one by also deferring the nullify of the ax->tty pointer. Otherwise, a NULL pointer dereference bug occurs. Partial of the stack trace is shown below. BUG: kernel NULL pointer dereference, address: 0000000000000538 RIP: 0010:ax_xmit+0x1f9/0x400 ... Call Trace: dev_hard_start_xmit+0xec/0x320 sch_direct_xmit+0xea/0x240 __qdisc_run+0x166/0x5c0 __dev_queue_xmit+0x2c7/0xaf0 ax25_std_establish_data_link+0x59/0x60 ax25_connect+0x3a0/0x500 ? security_socket_connect+0x2b/0x40 __sys_connect+0x96/0xc0 ? __hrtimer_init+0xc0/0xc0 ? common_nsleep+0x2e/0x50 ? switch_fpu_return+0x139/0x1a0 __x64_sys_connect+0x11/0x20 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The crash point is shown as below static void ax_encaps(...) { ... set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); // ax->tty = NULL! ... } By placing the nullify action after the unregister_netdev, the ax->tty pointer won't be assigned as NULL net_device framework layer is well synchronized. Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

hamradio: defer ax25 kfree after unregister_netdev

2021-12-29T10:50:30+00:00

commit 3e0588c291d6ce225f2b891753ca41d45ba42469 upstream. There is a possible race condition (use-after-free) like below (USE) | (FREE) ax25_sendmsg | ax25_queue_xmit | dev_queue_xmit | __dev_queue_xmit | __dev_xmit_skb | sch_direct_xmit | ... xmit_one | netdev_start_xmit | tty_ldisc_kill __netdev_start_xmit | mkiss_close ax_xmit | kfree ax_encaps | | Even though there are two synchronization primitives before the kfree: 1. wait_for_completion(&ax->dead). This can prevent the race with routines from mkiss_ioctl. However, it cannot stop the routine coming from upper layer, i.e., the ax25_sendmsg. 2. netif_stop_queue(ax->dev). It seems that this line of code aims to halt the transmit queue but it fails to stop the routine that already being xmit. This patch reorder the kfree after the unregister_netdev to avoid the possible UAF as the unregister_netdev() is well synchronized and won't return if there is a running routine. Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ax25: NPD bug when detaching AX25 device

2021-12-29T10:50:30+00:00

commit 1ade48d0c27d5da1ccf4b583d8c5fc8b534a3ac8 upstream. The existing cleanup routine implementation is not well synchronized with the syscall routine. When a device is detaching, below race could occur. static int ax25_sendmsg(...) { ... lock_sock() ax25 = sk_to_ax25(sk); if (ax25->ax25_dev == NULL) // CHECK ... ax25_queue_xmit(skb, ax25->ax25_dev->dev); // USE ... } static void ax25_kill_by_device(...) { ... if (s->ax25_dev == ax25_dev) { s->ax25_dev = NULL; ... } Other syscall functions like ax25_getsockopt, ax25_getname, ax25_info_show also suffer from similar races. To fix them, this patch introduce lock_sock() into ax25_kill_by_device in order to guarantee that the nullify action in cleanup routine cannot proceed when another socket request is pending. Signed-off-by: Hanjie Wu Signed-off-by: Lin Ma Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

xen/blkfront: fix bug in backported patch

2021-12-29T10:50:30+00:00

The backport of commit 8f5a695d99000fc ("xen/blkfront: don't take local copy of a request from the ring page") to stable 4.4 kernel introduced a bug when adding the needed blkif_ring_get_request() function, as info->ring.req_prod_pvt was incremented twice now. Fix that be deleting the now superfluous increments after calling that function. Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

ARM: 9169/1: entry: fix Thumb2 bug in iWMMXt exception handling

2021-12-29T10:50:30+00:00

commit 8536a5ef886005bc443c2da9b842d69fd3d7647f upstream. The Thumb2 version of the FP exception handling entry code treats the register holding the CP number (R8) differently, resulting in the iWMMXT CP number check to be incorrect. Fix this by unifying the ARM and Thumb2 code paths, and switch the order of the additions of the TI_USED_CP offset and the shifted CP index. Cc: Fixes: b86040a59feb ("Thumb-2: Implementation of the unified start-up and exceptions code") Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman

ALSA: drivers: opl3: Fix incorrect use of vp->state

2021-12-29T10:50:30+00:00

commit 2dee54b289fbc810669a1b2b8a0887fa1c9a14d7 upstream. Static analysis with scan-build has found an assignment to vp2 that is never used. It seems that the check on vp->state > 0 should be actually on vp2->state instead. Fix this. This dates back to 2002, I found the offending commit from the git history git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git, commit 91e39521bbf6 ("[PATCH] ALSA patch for 2.5.4") Signed-off-by: Colin Ian King Cc: Link: https://lore.kernel.org/r/20211212172025.470367-1-colin.i.king@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: jack: Check the return value of kstrdup()

2021-12-29T10:50:30+00:00

commit c01c1db1dc632edafb0dff32d40daf4f9c1a4e19 upstream. kstrdup() can return NULL, it is better to check the return value of it. Signed-off-by: Xiaoke Wang Cc: Link: https://lore.kernel.org/r/tencent_094816F3522E0DC704056C789352EBBF0606@qq.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

hwmon: (lm90) Fix usage of CONFIG2 register in detect function

2021-12-29T10:50:30+00:00

[ Upstream commit fce15c45d3fbd9fc1feaaf3210d8e3f8b33dfd3a ] The detect function had a comment "Make compiler happy" when id did not read the second configuration register. As it turns out, the code was checking the contents of this register for manufacturer ID 0xA1 (NXP Semiconductor/Philips), but never actually read the register. So it wasn't surprising that the compiler complained, and it indeed had a point. Fix the code to read the register contents for manufacturer ID 0xa1. At the same time, the code was reading the register for manufacturer ID 0x41 (Analog Devices), but it was not using the results. In effect it was just checking if reading the register returned an error. That doesn't really add much if any value, so stop doing that. Fixes: f90be42fb383 ("hwmon: (lm90) Refactor reading of config2 register") Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin