* [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends
@ 2022-05-10 3:57 Eric Dumazet
2022-05-10 3:57 ` [PATCH v2 net-next 1/5] net: add include/net/net_debug.h Eric Dumazet
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, Eric Dumazet, Eric Dumazet
From: Eric Dumazet <edumazet@google.com>
This patch series is inspired by some syzbot reports
hinting that skb transport_header might be not set
in places we expect it being set.
Add a new CONFIG_DEBUG_NET option
and DEBUG_NET_WARN_ON_ONCE() helper, so that we can start
adding more sanity checks in the future.
Replace two BUG() in skb_checksum_help()
with less risky code.
v2: make first patch compile on more arches/compilers
add the 5th patch to add more debugging in skb_checksum_help()
Eric Dumazet (5):
net: add include/net/net_debug.h
net: add CONFIG_DEBUG_NET
net: warn if transport header was not set
net: remove two BUG() from skb_checksum_help()
net: add more debug info in skb_checksum_help()
include/linux/netdevice.h | 141 +---------------------------------
include/linux/skbuff.h | 2 +
include/net/net_debug.h | 157 ++++++++++++++++++++++++++++++++++++++
net/Kconfig.debug | 7 ++
net/core/dev.c | 12 ++-
5 files changed, 176 insertions(+), 143 deletions(-)
create mode 100644 include/net/net_debug.h
--
2.36.0.512.ge40c2bad7a-goog
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v2 net-next 1/5] net: add include/net/net_debug.h 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet @ 2022-05-10 3:57 ` Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 2/5] net: add CONFIG_DEBUG_NET Eric Dumazet ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw) To: David S . Miller, Jakub Kicinski, Paolo Abeni Cc: netdev, Eric Dumazet, Eric Dumazet From: Eric Dumazet <edumazet@google.com> Remove from include/linux/netdevice.h helpers that send debug/info/warnings to syslog. We plan adding more helpers in following patches. v2: added two includes, and 'struct net_device' forward declaration to avoid compile errors (kernel bots) Signed-off-by: Eric Dumazet <edumazet@google.com> --- include/linux/netdevice.h | 141 +---------------------------------- include/net/net_debug.h | 151 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 152 insertions(+), 140 deletions(-) create mode 100644 include/net/net_debug.h diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 74c97a34921d48c593c08e2bed72e099f42520a3..5fb1de931bcb9d0caaa5449169012b192d69d892 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -50,6 +50,7 @@ #include <linux/hashtable.h> #include <linux/rbtree.h> #include <net/net_trackers.h> +#include <net/net_debug.h> struct netpoll_info; struct device; @@ -5050,81 +5051,9 @@ static inline const char *netdev_reg_state(const struct net_device *dev) return " (unknown)"; } -__printf(3, 4) __cold -void netdev_printk(const char *level, const struct net_device *dev, - const char *format, ...); -__printf(2, 3) __cold -void netdev_emerg(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_alert(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_crit(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_err(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_warn(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_notice(const struct net_device *dev, const char *format, ...); -__printf(2, 3) __cold -void netdev_info(const struct net_device *dev, const char *format, ...); - -#define netdev_level_once(level, dev, fmt, ...) \ -do { \ - static bool __section(".data.once") __print_once; \ - \ - if (!__print_once) { \ - __print_once = true; \ - netdev_printk(level, dev, fmt, ##__VA_ARGS__); \ - } \ -} while (0) - -#define netdev_emerg_once(dev, fmt, ...) \ - netdev_level_once(KERN_EMERG, dev, fmt, ##__VA_ARGS__) -#define netdev_alert_once(dev, fmt, ...) \ - netdev_level_once(KERN_ALERT, dev, fmt, ##__VA_ARGS__) -#define netdev_crit_once(dev, fmt, ...) \ - netdev_level_once(KERN_CRIT, dev, fmt, ##__VA_ARGS__) -#define netdev_err_once(dev, fmt, ...) \ - netdev_level_once(KERN_ERR, dev, fmt, ##__VA_ARGS__) -#define netdev_warn_once(dev, fmt, ...) \ - netdev_level_once(KERN_WARNING, dev, fmt, ##__VA_ARGS__) -#define netdev_notice_once(dev, fmt, ...) \ - netdev_level_once(KERN_NOTICE, dev, fmt, ##__VA_ARGS__) -#define netdev_info_once(dev, fmt, ...) \ - netdev_level_once(KERN_INFO, dev, fmt, ##__VA_ARGS__) - #define MODULE_ALIAS_NETDEV(device) \ MODULE_ALIAS("netdev-" device) -#if defined(CONFIG_DYNAMIC_DEBUG) || \ - (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) -#define netdev_dbg(__dev, format, args...) \ -do { \ - dynamic_netdev_dbg(__dev, format, ##args); \ -} while (0) -#elif defined(DEBUG) -#define netdev_dbg(__dev, format, args...) \ - netdev_printk(KERN_DEBUG, __dev, format, ##args) -#else -#define netdev_dbg(__dev, format, args...) \ -({ \ - if (0) \ - netdev_printk(KERN_DEBUG, __dev, format, ##args); \ -}) -#endif - -#if defined(VERBOSE_DEBUG) -#define netdev_vdbg netdev_dbg -#else - -#define netdev_vdbg(dev, format, args...) \ -({ \ - if (0) \ - netdev_printk(KERN_DEBUG, dev, format, ##args); \ - 0; \ -}) -#endif - /* * netdev_WARN() acts like dev_printk(), but with the key difference * of using a WARN/WARN_ON to get the message out, including the @@ -5138,74 +5067,6 @@ do { \ WARN_ONCE(1, "netdevice: %s%s: " format, netdev_name(dev), \ netdev_reg_state(dev), ##args) -/* netif printk helpers, similar to netdev_printk */ - -#define netif_printk(priv, type, level, dev, fmt, args...) \ -do { \ - if (netif_msg_##type(priv)) \ - netdev_printk(level, (dev), fmt, ##args); \ -} while (0) - -#define netif_level(level, priv, type, dev, fmt, args...) \ -do { \ - if (netif_msg_##type(priv)) \ - netdev_##level(dev, fmt, ##args); \ -} while (0) - -#define netif_emerg(priv, type, dev, fmt, args...) \ - netif_level(emerg, priv, type, dev, fmt, ##args) -#define netif_alert(priv, type, dev, fmt, args...) \ - netif_level(alert, priv, type, dev, fmt, ##args) -#define netif_crit(priv, type, dev, fmt, args...) \ - netif_level(crit, priv, type, dev, fmt, ##args) -#define netif_err(priv, type, dev, fmt, args...) \ - netif_level(err, priv, type, dev, fmt, ##args) -#define netif_warn(priv, type, dev, fmt, args...) \ - netif_level(warn, priv, type, dev, fmt, ##args) -#define netif_notice(priv, type, dev, fmt, args...) \ - netif_level(notice, priv, type, dev, fmt, ##args) -#define netif_info(priv, type, dev, fmt, args...) \ - netif_level(info, priv, type, dev, fmt, ##args) - -#if defined(CONFIG_DYNAMIC_DEBUG) || \ - (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) -#define netif_dbg(priv, type, netdev, format, args...) \ -do { \ - if (netif_msg_##type(priv)) \ - dynamic_netdev_dbg(netdev, format, ##args); \ -} while (0) -#elif defined(DEBUG) -#define netif_dbg(priv, type, dev, format, args...) \ - netif_printk(priv, type, KERN_DEBUG, dev, format, ##args) -#else -#define netif_dbg(priv, type, dev, format, args...) \ -({ \ - if (0) \ - netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \ - 0; \ -}) -#endif - -/* if @cond then downgrade to debug, else print at @level */ -#define netif_cond_dbg(priv, type, netdev, cond, level, fmt, args...) \ - do { \ - if (cond) \ - netif_dbg(priv, type, netdev, fmt, ##args); \ - else \ - netif_ ## level(priv, type, netdev, fmt, ##args); \ - } while (0) - -#if defined(VERBOSE_DEBUG) -#define netif_vdbg netif_dbg -#else -#define netif_vdbg(priv, type, dev, format, args...) \ -({ \ - if (0) \ - netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \ - 0; \ -}) -#endif - /* * The list of packet types we will receive (as opposed to discard) * and the routines to invoke. diff --git a/include/net/net_debug.h b/include/net/net_debug.h new file mode 100644 index 0000000000000000000000000000000000000000..19cd2700c20ea9945ae7662bacfa50f5d2bed398 --- /dev/null +++ b/include/net/net_debug.h @@ -0,0 +1,151 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_NET_DEBUG_H +#define _LINUX_NET_DEBUG_H + +#include <linux/bug.h> +#include <linux/kern_levels.h> + +struct net_device; + +__printf(3, 4) __cold +void netdev_printk(const char *level, const struct net_device *dev, + const char *format, ...); +__printf(2, 3) __cold +void netdev_emerg(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_alert(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_crit(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_err(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_warn(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_notice(const struct net_device *dev, const char *format, ...); +__printf(2, 3) __cold +void netdev_info(const struct net_device *dev, const char *format, ...); + +#define netdev_level_once(level, dev, fmt, ...) \ +do { \ + static bool __section(".data.once") __print_once; \ + \ + if (!__print_once) { \ + __print_once = true; \ + netdev_printk(level, dev, fmt, ##__VA_ARGS__); \ + } \ +} while (0) + +#define netdev_emerg_once(dev, fmt, ...) \ + netdev_level_once(KERN_EMERG, dev, fmt, ##__VA_ARGS__) +#define netdev_alert_once(dev, fmt, ...) \ + netdev_level_once(KERN_ALERT, dev, fmt, ##__VA_ARGS__) +#define netdev_crit_once(dev, fmt, ...) \ + netdev_level_once(KERN_CRIT, dev, fmt, ##__VA_ARGS__) +#define netdev_err_once(dev, fmt, ...) \ + netdev_level_once(KERN_ERR, dev, fmt, ##__VA_ARGS__) +#define netdev_warn_once(dev, fmt, ...) \ + netdev_level_once(KERN_WARNING, dev, fmt, ##__VA_ARGS__) +#define netdev_notice_once(dev, fmt, ...) \ + netdev_level_once(KERN_NOTICE, dev, fmt, ##__VA_ARGS__) +#define netdev_info_once(dev, fmt, ...) \ + netdev_level_once(KERN_INFO, dev, fmt, ##__VA_ARGS__) + +#if defined(CONFIG_DYNAMIC_DEBUG) || \ + (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) +#define netdev_dbg(__dev, format, args...) \ +do { \ + dynamic_netdev_dbg(__dev, format, ##args); \ +} while (0) +#elif defined(DEBUG) +#define netdev_dbg(__dev, format, args...) \ + netdev_printk(KERN_DEBUG, __dev, format, ##args) +#else +#define netdev_dbg(__dev, format, args...) \ +({ \ + if (0) \ + netdev_printk(KERN_DEBUG, __dev, format, ##args); \ +}) +#endif + +#if defined(VERBOSE_DEBUG) +#define netdev_vdbg netdev_dbg +#else + +#define netdev_vdbg(dev, format, args...) \ +({ \ + if (0) \ + netdev_printk(KERN_DEBUG, dev, format, ##args); \ + 0; \ +}) +#endif + +/* netif printk helpers, similar to netdev_printk */ + +#define netif_printk(priv, type, level, dev, fmt, args...) \ +do { \ + if (netif_msg_##type(priv)) \ + netdev_printk(level, (dev), fmt, ##args); \ +} while (0) + +#define netif_level(level, priv, type, dev, fmt, args...) \ +do { \ + if (netif_msg_##type(priv)) \ + netdev_##level(dev, fmt, ##args); \ +} while (0) + +#define netif_emerg(priv, type, dev, fmt, args...) \ + netif_level(emerg, priv, type, dev, fmt, ##args) +#define netif_alert(priv, type, dev, fmt, args...) \ + netif_level(alert, priv, type, dev, fmt, ##args) +#define netif_crit(priv, type, dev, fmt, args...) \ + netif_level(crit, priv, type, dev, fmt, ##args) +#define netif_err(priv, type, dev, fmt, args...) \ + netif_level(err, priv, type, dev, fmt, ##args) +#define netif_warn(priv, type, dev, fmt, args...) \ + netif_level(warn, priv, type, dev, fmt, ##args) +#define netif_notice(priv, type, dev, fmt, args...) \ + netif_level(notice, priv, type, dev, fmt, ##args) +#define netif_info(priv, type, dev, fmt, args...) \ + netif_level(info, priv, type, dev, fmt, ##args) + +#if defined(CONFIG_DYNAMIC_DEBUG) || \ + (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) +#define netif_dbg(priv, type, netdev, format, args...) \ +do { \ + if (netif_msg_##type(priv)) \ + dynamic_netdev_dbg(netdev, format, ##args); \ +} while (0) +#elif defined(DEBUG) +#define netif_dbg(priv, type, dev, format, args...) \ + netif_printk(priv, type, KERN_DEBUG, dev, format, ##args) +#else +#define netif_dbg(priv, type, dev, format, args...) \ +({ \ + if (0) \ + netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \ + 0; \ +}) +#endif + +/* if @cond then downgrade to debug, else print at @level */ +#define netif_cond_dbg(priv, type, netdev, cond, level, fmt, args...) \ + do { \ + if (cond) \ + netif_dbg(priv, type, netdev, fmt, ##args); \ + else \ + netif_ ## level(priv, type, netdev, fmt, ##args); \ + } while (0) + +#if defined(VERBOSE_DEBUG) +#define netif_vdbg netif_dbg +#else +#define netif_vdbg(priv, type, dev, format, args...) \ +({ \ + if (0) \ + netif_printk(priv, type, KERN_DEBUG, dev, format, ##args); \ + 0; \ +}) +#endif + + +#endif /* _LINUX_NET_DEBUG_H */ -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 net-next 2/5] net: add CONFIG_DEBUG_NET 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 1/5] net: add include/net/net_debug.h Eric Dumazet @ 2022-05-10 3:57 ` Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 3/5] net: warn if transport header was not set Eric Dumazet ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw) To: David S . Miller, Jakub Kicinski, Paolo Abeni Cc: netdev, Eric Dumazet, Eric Dumazet From: Eric Dumazet <edumazet@google.com> This config option enables network debugging checks. This patch adds DEBUG_NET_WARN_ON_ONCE(cond) Note that this is not a replacement for WARN_ON_ONCE(cond) as (cond) is not evaluated if CONFIG_DEBUG_NET is not set. Signed-off-by: Eric Dumazet <edumazet@google.com> --- include/net/net_debug.h | 6 ++++++ net/Kconfig.debug | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/include/net/net_debug.h b/include/net/net_debug.h index 19cd2700c20ea9945ae7662bacfa50f5d2bed398..1e74684cbbdbcd5ba304b935e76376a72d6ba3f2 100644 --- a/include/net/net_debug.h +++ b/include/net/net_debug.h @@ -148,4 +148,10 @@ do { \ #endif +#if defined(CONFIG_DEBUG_NET) +#define DEBUG_NET_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond) +#else +#define DEBUG_NET_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond) +#endif + #endif /* _LINUX_NET_DEBUG_H */ diff --git a/net/Kconfig.debug b/net/Kconfig.debug index 2f50611df858911cf5190a361e4e9316e543ed3a..a5781cf63b16b32e5360df1ca26a753b6505d81f 100644 --- a/net/Kconfig.debug +++ b/net/Kconfig.debug @@ -17,3 +17,10 @@ config NET_NS_REFCNT_TRACKER help Enable debugging feature to track netns references. This adds memory and cpu costs. + +config DEBUG_NET + bool "Add generic networking debug" + depends on DEBUG_KERNEL + help + Enable extra sanity checks in networking. + This is mostly used by fuzzers, but is safe to select. -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 net-next 3/5] net: warn if transport header was not set 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 1/5] net: add include/net/net_debug.h Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 2/5] net: add CONFIG_DEBUG_NET Eric Dumazet @ 2022-05-10 3:57 ` Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 4/5] net: remove two BUG() from skb_checksum_help() Eric Dumazet ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw) To: David S . Miller, Jakub Kicinski, Paolo Abeni Cc: netdev, Eric Dumazet, Eric Dumazet From: Eric Dumazet <edumazet@google.com> Make sure skb_transport_header() and skb_transport_offset() uses are not fooled if the transport header has not been set. This change will likely expose existing bugs in linux networking stacks. Signed-off-by: Eric Dumazet <edumazet@google.com> --- include/linux/skbuff.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d58669d6cb91aa30edc70d59a0a7e9d4e2298842..a1c73fccccc68641fe46066e6d1195b31483ca4c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -42,6 +42,7 @@ #if IS_ENABLED(CONFIG_NF_CONNTRACK) #include <linux/netfilter/nf_conntrack_common.h> #endif +#include <net/net_debug.h> /* The interface for checksum offload between the stack and networking drivers * is as follows... @@ -2804,6 +2805,7 @@ static inline bool skb_transport_header_was_set(const struct sk_buff *skb) static inline unsigned char *skb_transport_header(const struct sk_buff *skb) { + DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); return skb->head + skb->transport_header; } -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 net-next 4/5] net: remove two BUG() from skb_checksum_help() 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet ` (2 preceding siblings ...) 2022-05-10 3:57 ` [PATCH v2 net-next 3/5] net: warn if transport header was not set Eric Dumazet @ 2022-05-10 3:57 ` Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 5/5] net: add more debug info in skb_checksum_help() Eric Dumazet 2022-05-11 12:00 ` [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends patchwork-bot+netdevbpf 5 siblings, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw) To: David S . Miller, Jakub Kicinski, Paolo Abeni Cc: netdev, Eric Dumazet, Eric Dumazet From: Eric Dumazet <edumazet@google.com> I have a syzbot report that managed to get a crash in skb_checksum_help() If syzbot can trigger these BUG(), it makes sense to replace them with more friendly WARN_ON_ONCE() since skb_checksum_help() can instead return an error code. Note that syzbot will still crash there, until real bug is fixed. Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/core/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index f036ccb61da4da3ffc52c4f2402427054b831e8a..e12f8310dd86b312092c5d8fd50fa2ab60fce310 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3265,11 +3265,15 @@ int skb_checksum_help(struct sk_buff *skb) } offset = skb_checksum_start_offset(skb); - BUG_ON(offset >= skb_headlen(skb)); + ret = -EINVAL; + if (WARN_ON_ONCE(offset >= skb_headlen(skb))) + goto out; + csum = skb_checksum(skb, offset, skb->len - offset, 0); offset += skb->csum_offset; - BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb)); + if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) + goto out; ret = skb_ensure_writable(skb, offset + sizeof(__sum16)); if (ret) -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 net-next 5/5] net: add more debug info in skb_checksum_help() 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet ` (3 preceding siblings ...) 2022-05-10 3:57 ` [PATCH v2 net-next 4/5] net: remove two BUG() from skb_checksum_help() Eric Dumazet @ 2022-05-10 3:57 ` Eric Dumazet 2022-05-11 12:00 ` [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends patchwork-bot+netdevbpf 5 siblings, 0 replies; 7+ messages in thread From: Eric Dumazet @ 2022-05-10 3:57 UTC (permalink / raw) To: David S . Miller, Jakub Kicinski, Paolo Abeni Cc: netdev, Eric Dumazet, Eric Dumazet From: Eric Dumazet <edumazet@google.com> This is a followup of previous patch. Dumping the stack trace is a good start, but printing basic skb information is probably better. Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/core/dev.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index e12f8310dd86b312092c5d8fd50fa2ab60fce310..d3221ea4aab3bfded1d3d9e2b0d861afc1c2eed6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3266,15 +3266,17 @@ int skb_checksum_help(struct sk_buff *skb) offset = skb_checksum_start_offset(skb); ret = -EINVAL; - if (WARN_ON_ONCE(offset >= skb_headlen(skb))) + if (WARN_ON_ONCE(offset >= skb_headlen(skb))) { + DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); goto out; - + } csum = skb_checksum(skb, offset, skb->len - offset, 0); offset += skb->csum_offset; - if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) + if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) { + DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); goto out; - + } ret = skb_ensure_writable(skb, offset + sizeof(__sum16)); if (ret) goto out; -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet ` (4 preceding siblings ...) 2022-05-10 3:57 ` [PATCH v2 net-next 5/5] net: add more debug info in skb_checksum_help() Eric Dumazet @ 2022-05-11 12:00 ` patchwork-bot+netdevbpf 5 siblings, 0 replies; 7+ messages in thread From: patchwork-bot+netdevbpf @ 2022-05-11 12:00 UTC (permalink / raw) To: Eric Dumazet; +Cc: davem, kuba, pabeni, netdev, edumazet Hello: This series was applied to netdev/net-next.git (master) by David S. Miller <davem@davemloft.net>: On Mon, 9 May 2022 20:57:36 -0700 you wrote: > From: Eric Dumazet <edumazet@google.com> > > This patch series is inspired by some syzbot reports > hinting that skb transport_header might be not set > in places we expect it being set. > > Add a new CONFIG_DEBUG_NET option > and DEBUG_NET_WARN_ON_ONCE() helper, so that we can start > adding more sanity checks in the future. > > [...] Here is the summary with links: - [v2,net-next,1/5] net: add include/net/net_debug.h https://git.kernel.org/netdev/net-next/c/5b87be9e4978 - [v2,net-next,2/5] net: add CONFIG_DEBUG_NET https://git.kernel.org/netdev/net-next/c/d268c1f5cfc9 - [v2,net-next,3/5] net: warn if transport header was not set (no matching commit) - [v2,net-next,4/5] net: remove two BUG() from skb_checksum_help() https://git.kernel.org/netdev/net-next/c/d7ea0d9df2a6 - [v2,net-next,5/5] net: add more debug info in skb_checksum_help() https://git.kernel.org/netdev/net-next/c/eeee4b77dc52 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-05-11 12:00 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-05-10 3:57 [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 1/5] net: add include/net/net_debug.h Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 2/5] net: add CONFIG_DEBUG_NET Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 3/5] net: warn if transport header was not set Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 4/5] net: remove two BUG() from skb_checksum_help() Eric Dumazet 2022-05-10 3:57 ` [PATCH v2 net-next 5/5] net: add more debug info in skb_checksum_help() Eric Dumazet 2022-05-11 12:00 ` [PATCH v2 net-next 0/5] net: CONFIG_DEBUG_NET and friends patchwork-bot+netdevbpf
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