4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 569a933b03f3c48b392fe67c0086b3a6b9306b5a ]
Naresh reported an issue with the non-atomic memory allocation of cgroup local storage buffers:
[ 73.047526] BUG: sleeping function called from invalid context at /srv/oe/build/tmp-rpb-glibc/work-shared/intel-corei7-64/kernel-source/mm/slab.h:421 [ 73.060915] in_atomic(): 1, irqs_disabled(): 0, pid: 3157, name: test_cgroup_sto [ 73.068342] INFO: lockdep is turned off. [ 73.072293] CPU: 2 PID: 3157 Comm: test_cgroup_sto Not tainted 4.20.0-rc2-next-20181113 #1 [ 73.080548] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.0b 07/27/2017 [ 73.088018] Call Trace: [ 73.090463] dump_stack+0x70/0xa5 [ 73.093783] ___might_sleep+0x152/0x240 [ 73.097619] __might_sleep+0x4a/0x80 [ 73.101191] __kmalloc_node+0x1cf/0x2f0 [ 73.105031] ? cgroup_storage_update_elem+0x46/0x90 [ 73.109909] cgroup_storage_update_elem+0x46/0x90
cgroup_storage_update_elem() (as well as other update map update callbacks) is called with disabled preemption, so GFP_ATOMIC allocation should be used: e.g. alloc_htab_elem() in hashtab.c.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Tested-by: Naresh Kamboju naresh.kamboju@linaro.org Signed-off-by: Roman Gushchin guro@fb.com Cc: Alexei Starovoitov ast@kernel.org Cc: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/local_storage.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index 830d7f095748..fc1605aee5ea 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -138,7 +138,8 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *_key, return -ENOENT;
new = kmalloc_node(sizeof(struct bpf_storage_buffer) + - map->value_size, __GFP_ZERO | GFP_USER, + map->value_size, + __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN, map->numa_node); if (!new) return -ENOMEM;