In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()<\/p>\n
smc_llc_srv_add_link() keeps add_llc pointing into the queue entry:<\/p>\n
add_llc = &qentry->msg.add_link;\t\t\tsmc_llc.c:1482
\n …
\n smc_llc_save_add_link_info(link_new, add_llc);\tsmc_llc.c:1494
\n smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);\t\tsmc_llc.c:1495
\n …
\n u8 *llc_msg = smc_link_shared_v2_rxbuf(link) ?
\n\t(u8 *)lgr->wr_rx_buf_v2 : (u8 *)add_llc;\tsmc_llc.c:1504
\n smc_llc_save_add_link_rkeys(link, link_new, llc_msg);\tsmc_llc.c:1506<\/p>\n
smc_llc_flow_qentry_del() kfree()s the entry, so on a link without a shared
\nv2 receive buffer the pointer handed to smc_llc_save_add_link_rkeys() is
\nalready freed. Before the Fixes: commit that branch always used
\nlgr->wr_rx_buf_v2 and add_llc was not used after the free.<\/p>\n
Reproduced on an unpatched tree over rxe, with KASAN, kasan_multi_shot
\nand a link forced to max_recv_sge == 1: the entry is freed and read by
\nthe same call, and the freeing frame is smc_llc_srv_add_link() itself.<\/p>\n
[ 2.523161] BUG: KASAN: slab-use-after-free in smc_llc_save_add_link_rkeys+0x333\/0x350
\n [ 2.523499] Read of size 2 at addr ffff8880052194de by task kworker\/0:1\/11
\n [ 2.523789]
\n [ 2.523862] CPU: 0 UID: 0 PID: 11 Comm: kworker\/0:1 Not tainted 7.2.0-rc5-p0-g2c9dd296545d #35 PREEMPT(lazy)
\n [ 2.523865] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04\/01\/2014
\n [ 2.523866] Workqueue: smc_hs_wq smc_listen_work
\n [ 2.523869] Call Trace:
\n [ 2.523870]
\n [ 2.523871] dump_stack_lvl+0x53\/0x70
\n [ 2.523872] print_report+0xd0\/0x630
\n [ 2.523874] ? __pfx__raw_spin_lock_irqsave+0x10\/0x10
\n [ 2.523876] ? smc_llc_save_add_link_rkeys+0x333\/0x350
\n [ 2.523878] kasan_report+0xce\/0x100
\n [ 2.523879] ? smc_llc_save_add_link_rkeys+0x333\/0x350
\n [ 2.523881] smc_llc_save_add_link_rkeys+0x333\/0x350
\n [ 2.523883] ? smcr_buf_reg_lgr+0x2a4\/0x660
\n [ 2.523885] smc_llc_srv_add_link+0xaa2\/0x1e50
\n [ 2.523888] ? _printk+0xba\/0xf0
\n [ 2.523897] ? __pfx_smc_llc_srv_add_link+0x10\/0x10
\n [ 2.523899] ? down_write+0xb0\/0x130
\n [ 2.523903] ? __pfx_down_write+0x10\/0x10
\n [ 2.523905] smc_listen_work+0x489e\/0x4d00
\n [ 2.523907] ? kmem_cache_free+0x1c6\/0x3a0
\n [ 2.523911] ? __pfx_smc_listen_work+0x10\/0x10
\n [ 2.523913] ? release_sock+0x148\/0x1d0
\n [ 2.523915] ? smc_tcp_listen_work+0xb4f\/0xfc0
\n [ 2.523917] ? _raw_spin_lock_irq+0x80\/0xe0
\n [ 2.523918] ? __pfx__raw_spin_lock_irq+0x10\/0x10
\n [ 2.523920] process_one_work+0x633\/0x1030
\n [ 2.523922] ? assign_work+0x11d\/0x370
\n [ 2.523924] worker_thread+0x45b\/0xd10
\n [ 2.523926] ? __pfx_worker_thread+0x10\/0x10
\n [ 2.523928] ? __pfx_worker_thread+0x10\/0x10
\n [ 2.523929] kthread+0x2c6\/0x3b0
\n [ 2.523931] ? recalc_sigpending+0x15c\/0x1e0
\n [ 2.523934] ? __pfx_kthread+0x10\/0x10
\n [ 2.523935] ret_from_fork+0x36e\/0x5a0
\n [ 2.523937] ? __pfx_ret_from_fork+0x10\/0x10
\n [ 2.523938] ? __switch_to+0x572\/0xdd0
\n [ 2.523943] ? __pfx_kthread+0x10\/0x10
\n [ 2.523944] ret_from_fork_asm+0x1a\/0x30
\n [ 2.523947]
\n [ 2.523948]
\n [ 2.531253] Allocated by task 48:
\n [ 2.531399] kasan_save_stack+0x33\/0x60
\n [ 2.531570] kasan_save_track+0x14\/0x30
\n [ 2.531737] __kasan_kmalloc+0x8f\/0xa0
\n [ 2.531905] __kmalloc_cache_noprof+0x158\/0x370
\n [ 2.532100] smc_llc_enqueue+0x72\/0x560
\n [ 2.532268] smc_wr_rx_tasklet_fn+0x474\/0xa80
\n [ 2.532491] tasklet_action_common+0x20f\/0x8a0
\n [ 2.532714] handle_softirqs+0x18e\/0x590
\n [ 2.532886] do_softirq+0x3b\/0x60
\n [ 2.533036] __local_bh_enable_ip+0x61\/0x70
\n [ 2.533221] __alloc_skb+0x732\/0x890
\n [ 2.533384] rxe_init_packet+0x16b\/0x4f0
\n [ 2.533567] prepare_ack_packet+0xb8\/0x830
\n [ 2.533760] rxe_receiver+0x495\/0x96e0
\n [ 2.533933] do_work+0x144\/0x470
\n [ 2
\n—truncated—<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()<\/p>\n
smc_llc_srv_add_link() keeps add_llc pointing into the que<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21314","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21314","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21314"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21314"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21314"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}