The commit is pushed to "branch-rh8-4.18.0-193.6.3.vz8.4.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh8-4.18.0-193.6.3.vz8.4.7 ------> commit d77ff0bac7444625507cf0419d57bd3d72972801 Author: Andrey Ryabinin <aryabi...@virtuozzo.com> Date: Tue Sep 15 11:55:26 2020 +0300
keys, user: Fix high order allocation in user_instantiate() #PSBM-107794 Adding user key might trigger 4-order allocation which is unreliable in case of fragmented memory: ------------[ cut here ]------------ WARNING: CPU: 3 PID: 134927 at mm/page_alloc.c:3533 __alloc_pages_nodemask+0x1b1/0x600 order 4 >= 3, gfp 0x40d0 Kernel panic - not syncing: panic_on_warn set ... CPU: 3 PID: 134927 Comm: add_key01 ve: 0 Kdump: loaded Tainted: G OE ------------ 3.10.0-1127.18.2.vz7.163.15 #1 163.15 Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.2 04/01/2014 Call Trace: dump_stack+0x19/0x1b panic+0xe8/0x21f __warn+0xfa/0x100 warn_slowpath_fmt+0x5f/0x80 __alloc_pages_nodemask+0x1b1/0x600 alloc_pages_current+0x98/0x110 kmalloc_order+0x18/0x40 kmalloc_order_trace+0x26/0xa0 __kmalloc+0x281/0x2a0 user_instantiate+0x47/0x90 __key_instantiate_and_link+0x54/0x100 key_create_or_update+0x398/0x490 SyS_add_key+0x12c/0x220 system_call_fastpath+0x25/0x2a Use kvmalloc() to avoid potential -ENOMEM due to fragmentation. https://jira.sw.ru/browse/PSBM-107794 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> (cherry picked from commit 499126f3b029a72e2883b386c94fe4fc94f32c91) Signed-off-by: Konstantin Khorenko <khore...@virtuozzo.com> --- security/keys/user_defined.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 9f558bedba23..39add3cd78ef 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -9,6 +9,7 @@ * 2 of the License, or (at your option) any later version. */ +#include <linux/mm.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> @@ -68,7 +69,7 @@ int user_preparse(struct key_preparsed_payload *prep) if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; - upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); + upayload = kvmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); if (!upayload) return -ENOMEM; @@ -86,7 +87,10 @@ EXPORT_SYMBOL_GPL(user_preparse); */ void user_free_preparse(struct key_preparsed_payload *prep) { - kzfree(prep->payload.data[0]); + struct user_key_payload *upayload = prep->payload.data[0]; + + memset(upayload, 0, sizeof(*upayload) + upayload->datalen); + kvfree(upayload); } EXPORT_SYMBOL_GPL(user_free_preparse); @@ -95,7 +99,8 @@ static void user_free_payload_rcu(struct rcu_head *head) struct user_key_payload *payload; payload = container_of(head, struct user_key_payload, rcu); - kzfree(payload); + memset(payload, 0, sizeof(*payload) + payload->datalen); + kvfree(payload); } /* @@ -151,7 +156,8 @@ void user_destroy(struct key *key) { struct user_key_payload *upayload = key->payload.data[0]; - kzfree(upayload); + memset(upayload, 0, sizeof(*upayload) + upayload->datalen); + kvfree(upayload); } EXPORT_SYMBOL_GPL(user_destroy); _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel