kernel/linux.git/net/core/dev_ioctl.c, branch v6.18.21

net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()

2025-11-14T01:23:21+00:00

The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL. Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config") Closes: https://lore.kernel.org/cd6a7056-fa6d-43f8-b78a-f5e811247ba8@linux.dev Signed-off-by: Jiaming Zhang Reviewed-by: Kory Maincent Link: https://patch.msgid.link/20251111173652.749159-2-r772577952@gmail.com Signed-off-by: Jakub Kicinski

net: dev_ioctl: take ops lock in hwtstamp lower paths

2025-09-10T01:13:36+00:00

ndo hwtstamp callbacks are expected to run under the per-device ops lock. Make the lower get/set paths consistent with the rest of ndo invocations. Kernel log: WARNING: CPU: 13 PID: 51364 at ./include/net/netdev_lock.h:70 __netdev_update_features+0x4bd/0xe60 ... RIP: 0010:__netdev_update_features+0x4bd/0xe60 ... Call Trace: netdev_update_features+0x1f/0x60 mlx5_hwtstamp_set+0x181/0x290 [mlx5_core] mlx5e_hwtstamp_set+0x19/0x30 [mlx5_core] dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp+0x13d/0x240 dev_ioctl+0x12f/0x4b0 sock_ioctl+0x171/0x370 __x64_sys_ioctl+0x3f7/0x900 ? __sys_setsockopt+0x69/0xb0 do_syscall_64+0x6f/0x2e0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... .... ---[ end trace 0000000000000000 ]--- Note that the mlx5_hwtstamp_set and mlx5e_hwtstamp_set functions shown in the trace come from an in progress patch converting the legacy ioctl to ndo_hwtstamp_get/set and are not present in mainline. Fixes: ffb7ed19ac0a ("net: hold netdev instance lock during ioctl operations") Signed-off-by: Carolina Jubran Reviewed-by: Cosmin Ratiu Reviewed-by: Dragos Tatulea Link: https://patch.msgid.link/20250907080821.2353388-1-cjubran@nvidia.com Signed-off-by: Jakub Kicinski

net: s/dev_get_flags/netif_get_flags/

2025-07-19T00:27:47+00:00

Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250717172333.1288349-6-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: s/dev_get_mac_address/netif_get_mac_address/

2025-07-19T00:27:46+00:00

Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. netif_get_mac_address is used only by tun/tap, so move it into NETDEV_INTERNAL namespace. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250717172333.1288349-3-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: core: Convert dev_set_mac_address_user() to use struct sockaddr_storage

2025-05-27T06:25:43+00:00

Convert callers of dev_set_mac_address_user() to use struct sockaddr_storage. Add sanity checks on dev->addr_len usage. Signed-off-by: Kees Cook Acked-by: Gustavo A. R. Silva Link: https://patch.msgid.link/20250521204619.2301870-8-kees@kernel.org Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-03-26T16:32:10+00:00

Merge in late fixes to prepare for the 6.15 net-next PR. No conflicts, adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt.c 919f9f497dbc ("eth: bnxt: fix out-of-range access of vnic_info array") fe96d717d38e ("bnxt_en: Extend queue stop/start for TX rings") Signed-off-by: Jakub Kicinski

net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

2025-03-21T21:10:06+00:00

SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller Reported-by: yan kang Reported-by: yue sun Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P300MB0421.AUSP300.PROD.OUTLOOK.COM/ Signed-off-by: Kuniyuki Iwashima Acked-by: Stanislav Fomichev Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni

Revert "net: replace dev_addr_sem with netdev instance lock"

2025-03-19T17:52:00+00:00

This reverts commit df43d8bf10316a7c3b1e47e3cc0057a54df4a5b8. Cc: Kohei Enju Reviewed-by: Kuniyuki Iwashima Fixes: df43d8bf1031 ("net: replace dev_addr_sem with netdev instance lock") Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250312190513.1252045-2-sdf@fomichev.me Tested-by: Lei Yang Signed-off-by: Paolo Abeni

net: move misc netdev_lock flavors to a separate header

2025-03-08T17:06:50+00:00

Move the more esoteric helpers for netdev instance lock to a dedicated header. This avoids growing netdevice.h to infinity and makes rebuilding the kernel much faster (after touching the header with the helpers). The main netdev_lock() / netdev_unlock() functions are used in static inlines in netdevice.h and will probably be used most commonly, so keep them in netdevice.h. Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: replace dev_addr_sem with netdev instance lock

2025-03-06T20:59:45+00:00

Lockdep reports possible circular dependency in [0]. Instead of fixing the ordering, replace global dev_addr_sem with netdev instance lock. Most of the paths that set/get mac are RTNL protected. Two places where it's not, convert to explicit locking: - sysfs address_show - dev_get_mac_address via dev_ioctl 0: https://netdev-3.bots.linux.dev/vmksft-forwarding-dbg/results/993321/24-router-bridge-1d-lag-sh/stderr Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250305163732.2766420-12-sdf@fomichev.me Signed-off-by: Jakub Kicinski