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path: root/privs.c
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#include <unistd.h>
#include <sys/types.h>

#include "privs.h"
#include "die.h"

void drop_privileges(bool enforce, uid_t uid, gid_t gid)
{
	if (enforce) {
		if (uid == getuid())
			panic("Uid cannot be the same as the current user!\n");
		if (gid == getgid())
			panic("Gid cannot be the same as the current user!\n");
	}
	if (setgid(gid) != 0)
		panic("Unable to drop group privileges: %s!\n", strerror(errno));
	if (setuid(uid) != 0)
		panic("Unable to drop user privileges: %s!\n", strerror(errno));
}
ption value='1'>ssdiff
authorEric Dumazet <edumazet@google.com>2017-01-27 08:11:44 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-29 18:30:56 -0500
commitf1712c73714088a7252d276a57126d56c7d37e64 (patch)
tree962ee49daf8d1cba8403fcf03b315d4a142ec944 /drivers/usb/host/Makefile
parentdc97a89e726c4e1830320d1db8215ef77ecebae0 (diff)
can: Fix kernel panic at security_sock_rcv_skb
Zhang Yanmin reported crashes [1] and provided a patch adding a synchronize_rcu() call in can_rx_unregister() The main problem seems that the sockets themselves are not RCU protected. If CAN uses RCU for delivery, then sockets should be freed only after one RCU grace period. Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's ease stable backports with the following fix instead. [1] BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0 Call Trace: <IRQ> [<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60 [<ffffffff81d55771>] sk_filter+0x41/0x210 [<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0 [<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0 [<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370 [<ffffffff81f07af9>] can_receive+0xd9/0x120 [<ffffffff81f07beb>] can_rcv+0xab/0x100 [<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0 [<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0 [<ffffffff81d37f67>] process_backlog+0x127/0x280 [<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0 [<ffffffff810c88d4>] __do_softirq+0x184/0x440 [<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30 <EOI> [<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40 [<ffffffff810c8bed>] do_softirq+0x1d/0x20 [<ffffffff81d30085>] netif_rx_ni+0xe5/0x110 [<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520 [<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230 [<ffffffff810e3baf>] process_one_work+0x24f/0x670 [<ffffffff810e44ed>] worker_thread+0x9d/0x6f0 [<ffffffff810e4450>] ? rescuer_thread+0x480/0x480 [<ffffffff810ebafc>] kthread+0x12c/0x150 [<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70 Reported-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/usb/host/Makefile')