diff options
Diffstat (limited to 'bpf-fix-bpf_jit_limit-knob.patch')
| -rw-r--r-- | bpf-fix-bpf_jit_limit-knob.patch | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/bpf-fix-bpf_jit_limit-knob.patch b/bpf-fix-bpf_jit_limit-knob.patch deleted file mode 100644 index 68c9d967c..000000000 --- a/bpf-fix-bpf_jit_limit-knob.patch +++ /dev/null @@ -1,173 +0,0 @@ -From fdadd04931c2d7cd294dc5b2b342863f94be53a3 Mon Sep 17 00:00:00 2001 -From: Daniel Borkmann <daniel@iogearbox.net> -Date: Tue, 11 Dec 2018 12:14:12 +0100 -Subject: bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K - -Michael and Sandipan report: - - Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF - JIT allocations. At compile time it defaults to PAGE_SIZE * 40000, - and is adjusted again at init time if MODULES_VADDR is defined. - - For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with - the compile-time default at boot-time, which is 0x9c400000 when - using 64K page size. This overflows the signed 32-bit bpf_jit_limit - value: - - root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit - -1673527296 - - and can cause various unexpected failures throughout the network - stack. In one case `strace dhclient eth0` reported: - - setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8}, - 16) = -1 ENOTSUPP (Unknown error 524) - - and similar failures can be seen with tools like tcpdump. This doesn't - always reproduce however, and I'm not sure why. The more consistent - failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9 - host would time out on systemd/netplan configuring a virtio-net NIC - with no noticeable errors in the logs. - -Given this and also given that in near future some architectures like -arm64 will have a custom area for BPF JIT image allocations we should -get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For -4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec() -so therefore add another overridable bpf_jit_alloc_exec_limit() helper -function which returns the possible size of the memory area for deriving -the default heuristic in bpf_jit_charge_init(). - -Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new -bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default -JIT memory provider, and therefore in case archs implement their custom -module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for -vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}. - -Additionally, for archs supporting large page sizes, we should change -the sysctl to be handled as long to not run into sysctl restrictions -in future. - -Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") -Reported-by: Sandipan Das <sandipan@linux.ibm.com> -Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com> -Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> -Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com> -Signed-off-by: Alexei Starovoitov <ast@kernel.org> ---- - include/linux/filter.h | 2 +- - kernel/bpf/core.c | 21 +++++++++++++++------ - net/core/sysctl_net_core.c | 20 +++++++++++++++++--- - 3 files changed, 33 insertions(+), 10 deletions(-) - -diff --git a/include/linux/filter.h b/include/linux/filter.h -index 795ff0b869bb..a8b9d90a8042 100644 ---- a/include/linux/filter.h -+++ b/include/linux/filter.h -@@ -861,7 +861,7 @@ bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk, - extern int bpf_jit_enable; - extern int bpf_jit_harden; - extern int bpf_jit_kallsyms; --extern int bpf_jit_limit; -+extern long bpf_jit_limit; - - typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); - -diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c -index b1a3545d0ec8..b2890c268cb3 100644 ---- a/kernel/bpf/core.c -+++ b/kernel/bpf/core.c -@@ -365,13 +365,11 @@ void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) - } - - #ifdef CONFIG_BPF_JIT --# define BPF_JIT_LIMIT_DEFAULT (PAGE_SIZE * 40000) -- - /* All BPF JIT sysctl knobs here. */ - int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); - int bpf_jit_harden __read_mostly; - int bpf_jit_kallsyms __read_mostly; --int bpf_jit_limit __read_mostly = BPF_JIT_LIMIT_DEFAULT; -+long bpf_jit_limit __read_mostly; - - static __always_inline void - bpf_get_prog_addr_region(const struct bpf_prog *prog, -@@ -580,16 +578,27 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, - - static atomic_long_t bpf_jit_current; - -+/* Can be overridden by an arch's JIT compiler if it has a custom, -+ * dedicated BPF backend memory area, or if neither of the two -+ * below apply. -+ */ -+u64 __weak bpf_jit_alloc_exec_limit(void) -+{ - #if defined(MODULES_VADDR) -+ return MODULES_END - MODULES_VADDR; -+#else -+ return VMALLOC_END - VMALLOC_START; -+#endif -+} -+ - static int __init bpf_jit_charge_init(void) - { - /* Only used as heuristic here to derive limit. */ -- bpf_jit_limit = min_t(u64, round_up((MODULES_END - MODULES_VADDR) >> 2, -- PAGE_SIZE), INT_MAX); -+ bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, -+ PAGE_SIZE), LONG_MAX); - return 0; - } - pure_initcall(bpf_jit_charge_init); --#endif - - static int bpf_jit_charge_modmem(u32 pages) - { -diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c -index 37b4667128a3..d67ec17f2cc8 100644 ---- a/net/core/sysctl_net_core.c -+++ b/net/core/sysctl_net_core.c -@@ -28,6 +28,8 @@ static int two __maybe_unused = 2; - static int min_sndbuf = SOCK_MIN_SNDBUF; - static int min_rcvbuf = SOCK_MIN_RCVBUF; - static int max_skb_frags = MAX_SKB_FRAGS; -+static long long_one __maybe_unused = 1; -+static long long_max __maybe_unused = LONG_MAX; - - static int net_msg_warn; /* Unused, but still a sysctl */ - -@@ -289,6 +291,17 @@ proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write, - - return proc_dointvec_minmax(table, write, buffer, lenp, ppos); - } -+ -+static int -+proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write, -+ void __user *buffer, size_t *lenp, -+ loff_t *ppos) -+{ -+ if (!capable(CAP_SYS_ADMIN)) -+ return -EPERM; -+ -+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); -+} - #endif - - static struct ctl_table net_core_table[] = { -@@ -398,10 +411,11 @@ static struct ctl_table net_core_table[] = { - { - .procname = "bpf_jit_limit", - .data = &bpf_jit_limit, -- .maxlen = sizeof(int), -+ .maxlen = sizeof(long), - .mode = 0600, -- .proc_handler = proc_dointvec_minmax_bpf_restricted, -- .extra1 = &one, -+ .proc_handler = proc_dolongvec_minmax_bpf_restricted, -+ .extra1 = &long_one, -+ .extra2 = &long_max, - }, - #endif - { --- -cgit 1.2-0.3.lf.el7 - |