sched: address a potential NULL pointer dereference in the GRED scheduler.

[ Upstream commit 115ef44a98 ]

If kzalloc in gred_init returns a NULL pointer, the code follows the
error handling path, invoking gred_destroy. This, in turn, calls
gred_offload, where memset could receive a NULL pointer as input,
potentially leading to a kernel crash.

When table->opt is NULL in gred_init(), gred_change_table_def()
is not called yet, so it is not necessary to call ->ndo_setup_tc()
in gred_offload().

Signed-off-by: Jun Yang <juny24602@gmail.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: f25c0515c5 ("net: sched: gred: dynamically allocate tc_gred_qopt_offload")
Link: https://patch.msgid.link/20250305154410.3505642-1-juny24602@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

This commit is contained in:

Jun Yang

2025-03-05 23:44:10 +08:00

committed by

Greg Kroah-Hartman

parent 0befa32ac3

commit 68896dd501

1 changed files with 2 additions and 1 deletions

									
										net/sched/sch_gred.c
									
		+2
		-1
	
												View File
												
				@@ -913,7 +913,8 @@ static void gred_destroy(struct Qdisc *sch)

					for (i = 0; i < table->DPs; i++)

						gred_destroy_vq(table->tab[i]);

					gred_offload(sch, TC_GRED_DESTROY);

					if (table->opt)

						gred_offload(sch, TC_GRED_DESTROY);

					kfree(table->opt);

				}