In the Linux kernel, the following vulnerability has been resolved:
smb: client: Fix use-after-free of network namespace.
Recently, we got a customer report that CIFS triggers oops while reconnecting to a server. [0]
The workload runs on Kubernetes, and some pods mount CIFS servers in non-root network namespaces. The problem rarely happened, but it was always while the pod was dying.
The root cause is wrong reference counting for network namespace.
CIFS uses kernel sockets, which do not hold refcnt of the netns that the socket belongs to. That means CIFS must ensure the socket is always freed before its netns; otherwise, use-after-free happens.
The repro steps are roughly:
1. mount CIFS in a non-root netns 2. drop packets from the netns 3. destroy the netns 4. unmount CIFS
We can reproduce the issue quickly with the script [1] below and see the splat [2] if CONFIGNETNSREFCNTTRACKER is enabled.
When the socket is TCP, it is hard to guarantee the netns lifetime without holding refcnt due to async timers.
Let's hold netns refcnt for each socket as done for SMC in commit 9744d2bf1976 ("smc: Fix use-after-free in tcpwritetimerhandler().").
Note that we need to move putnet() from cifsputtcpsession() to cleandemultiplexinfo(); otherwise, sockcreate() still could touch a freed netns while cifsd tries to reconnect from cifsdemultiplexthread().
Also, maybegetnet() cannot be put just before sockcreate() because the code is not under RCU and there is a small chance that the same address happened to be reallocated to another netns.
[0]: CIFS: VFS: \\XXXXXXXXXXX has not responded in 15 seconds. Reconnecting... CIFS: Serverclose failed 4 times, giving up Unable to handle kernel paging request at virtual address 14de99e461f84a07 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [14de99e461f84a07] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: clsbpf schingress nlsutf8 cifs cifsarc4 cifsmd4 dnsresolver tcpdiag inetdiag veth xtstate xtconnmark nfconntracknetlink xtnat xtstatistic xtMASQUERADE xtmark xtaddrtype iptREJECT nfrejectipv4 nftchainnat nfnat xtconntrack nfconntrack nfdefragipv6 nfdefragipv4 xtcomment nftcompat nftables nfnetlink overlay nlsascii nlscp437 sunrpc vfat fat aesceblk aescecipher ghashce sm4cecipher sm4 sm3ce sm3 sha3ce sha512ce sha512arm64 sha1ce ena button schfqcodel loop fuse configfs dmisysfs sha2ce sha256arm64 dmmirror dmregionhash dmlog dmmod dax efivarfs CPU: 5 PID: 2690970 Comm: cifsd Not tainted 6.1.103-109.184.amzn2023.aarch64 #1 Hardware name: Amazon EC2 r7g.4xlarge/, BIOS 1.0 11/1/2018 pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : fibruleslookup+0x44/0x238 lr : fiblookup+0x64/0xbc sp : ffff8000265db790 x29: ffff8000265db790 x28: 0000000000000000 x27: 000000000000bd01 x26: 0000000000000000 x25: ffff000b4baf8000 x24: ffff00047b5e4580 x23: ffff8000265db7e0 x22: 0000000000000000 x21: ffff00047b5e4500 x20: ffff0010e3f694f8 x19: 14de99e461f849f7 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 3f92800abd010002 x11: 0000000000000001 x10: ffff0010e3f69420 x9 : ffff800008a6f294 x8 : 0000000000000000 x7 : 0000000000000006 x6 : 0000000000000000 x5 : 0000000000000001 x4 : ffff001924354280 x3 : ffff8000265db7e0 x2 : 0000000000000000 x1 : ffff0010e3f694f8 x0 : ffff00047b5e4500 Call trace: fibruleslookup+0x44/0x238 fiblookup+0x64/0xbc iprouteoutputkeyhashrcu+0x2c4/0x398 iprouteoutputkeyhash+0x60/0x8c tcpv4connect+0x290/0x488 inetstreamconnect+0x108/0x3d0 inetstreamconnect+0x50/0x78 kernelconnect+0x6c/0xac genericipconne ---truncated---
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Add sendpageok() check to disable MSGSPLICEPAGES
While running ISER over SIW, the initiator machine encounters a warning from skbsplicefromiter() indicating that a slab page is being used in sendpage. To address this, it is better to add a sendpageok() check within the driver itself, and if it returns 0, then MSGSPLICEPAGES flag should be disabled before entering the network stack.
A similar issue has been discussed for NVMe in this thread: https://lore.kernel.org/all/20240530142417.146696-1-ofir.gal@volumez.com/
WARNING: CPU: 0 PID: 5342 at net/core/skbuff.c:7140 skbsplicefromiter+0x173/0x320 Call Trace: tcpsendmsglocked+0x368/0xe40 siwtxhdt+0x695/0xa40 [siw] siwqpsqprocess+0x102/0xb00 [siw] siwsqresume+0x39/0x110 [siw] siwrunsq+0x74/0x160 [siw] kthread+0xd2/0x100 retfromfork+0x34/0x40 retfromforkasm+0x1a/0x30
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-use-after-free in ksmbdsmb2sessioncreate
There is a race condition between ksmbdsmb2sessioncreate and ksmbdexpiresession. This patch add missing sessionstablelock while adding/deleting session from global session table.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix slab-use-after-free in smb3preauthhashrsp
ksmbdusersessionput should be called under smb3preauthhashrsp(). It will avoid freeing session before calling smb3preauthhashrsp().
In the Linux kernel, the following vulnerability has been resolved:
net: vertexcom: mse102x: Fix possible double free of TX skb
The scope of the TX skb is wider than just mse102xtxframespi(), so in case the TX skb room needs to be expanded, we should free the the temporary skb instead of the original skb. Otherwise the original TX skb pointer would be freed again in mse102xtxwork(), which leads to crashes:
Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G D 6.6.23 Hardware name: chargebyte Charge SOM DC-ONE (DT) Workqueue: events mse102xtxwork [mse102x] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skbreleasedata+0xb8/0x1d8 lr : skbreleasedata+0x1ac/0x1d8 sp : ffff8000819a3cc0 x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0 x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50 x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000 x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000 x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8 x8 : fffffc00001bc008 x7 : 0000000000000000 x6 : 0000000000000008 x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009 x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000 Call trace: skbreleasedata+0xb8/0x1d8 kfreeskbreason+0x48/0xb0 mse102xtxwork+0x164/0x35c [mse102x] processonework+0x138/0x260 workerthread+0x32c/0x438 kthread+0x118/0x11c retfromfork+0x10/0x20 Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: mtkethsoc: fix memory corruption during fq dma init
The loop responsible for allocating up to MTKFQDMALENGTH buffers must only touch as many descriptors, otherwise it ends up corrupting unrelated memory. Fix the loop iteration count accordingly.
In the Linux kernel, the following vulnerability has been resolved:
tcp/dccp: Don't use timerpending() in reqskqueueunlink().
Martin KaFai Lau reported use-after-free [0] in reqsktimerhandler().
""" We are seeing a use-after-free from a bpf prog attached to tracetcpretransmitsynack. The program passes the req->sk to the bpfskstoragegettracing kernel helper which does check for null before using it. """
The commit 83fccfc3940c ("inet: fix potential deadlock in reqskqueueunlink()") added timerpending() in reqskqueueunlink() not to call deltimersync() from reqsktimerhandler(), but it introduced a small race window.
Before the timer is called, expiretimers() calls detachtimer(timer, true) to clear timer->entry.pprev and marks it as not pending.
If reqskqueueunlink() checks timerpending() just after expiretimers() calls detachtimer(), TCP will miss deltimersync(); the reqsk timer will continue running and send multiple SYN+ACKs until it expires.
The reported UAF could happen if req->sk is close()d earlier than the timer expiration, which is 63s by default.
The scenario would be
1. inetcskcompletehashdance() calls inetcskreqskqueuedrop(), but deltimersync() is missed
2. reqsk timer is executed and scheduled again
3. req->sk is accept()ed and reqskput() decrements rskrefcnt, but reqsk timer still has another one, and inetcskaccept() does not clear req->sk for non-TFO sockets
4. sk is close()d
5. reqsk timer is executed again, and BPF touches req->sk
Let's not use timerpending() by passing the caller context to inetcskreqskqueuedrop().
Note that reqsk timer is pinned, so the issue does not happen in most use cases. [1]
[0] BUG: KFENCE: use-after-free read in bpfskstoragegettracing+0x2e/0x1b0
Use-after-free read at 0x00000000a891fb3a (in kfence-#1): bpfskstoragegettracing+0x2e/0x1b0 bpfprog5ea3e95db6da0438tcpretransmitsynack+0x1d20/0x1dda bpftracerun2+0x4c/0xc0 tcprtxsynack+0xf9/0x100 reqsktimerhandler+0xda/0x3d0 runtimersoftirq+0x292/0x8a0 irqexitrcu+0xf5/0x320 sysvecapictimerinterrupt+0x6d/0x80 asmsysvecapictimerinterrupt+0x16/0x20 intelidleirq+0x5a/0xa0 cpuidleenterstate+0x94/0x273 cpustartupentry+0x15e/0x260 startsecondary+0x8a/0x90 secondarystartup64noverify+0xfa/0xfb
kfence-#1: 0x00000000a72cc7b6-0x00000000d97616d9, size=2376, cache=TCPv6
allocated by task 0 on cpu 9 at 260507.901592s: skprotalloc+0x35/0x140 skclonelock+0x1f/0x3f0 inetcskclonelock+0x15/0x160 tcpcreateopenreqchild+0x1f/0x410 tcpv6synrecvsock+0x1da/0x700 tcpcheckreq+0x1fb/0x510 tcpv6rcv+0x98b/0x1420 ipv6listrcv+0x2258/0x26e0 napicompletedone+0x5b1/0x2990 mlx5enapipoll+0x2ae/0x8d0 netrxaction+0x13e/0x590 irqexitrcu+0xf5/0x320 commoninterrupt+0x80/0x90 asmcommoninterrupt+0x22/0x40 cpuidleenterstate+0xfb/0x273 cpustartupentry+0x15e/0x260 startsecondary+0x8a/0x90 secondarystartup64noverify+0xfa/0xfb
freed by task 0 on cpu 9 at 260507.927527s: rcucoresi+0x4ff/0xf10 irqexitrcu+0xf5/0x320 sysvecapictimerinterrupt+0x6d/0x80 asmsysvecapictimerinterrupt+0x16/0x20 cpuidleenterstate+0xfb/0x273 cpustartupentry+0x15e/0x260 startsecondary+0x8a/0x90 secondarystartup64noverify+0xfa/0xfb
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix possible double free in smb2setea()
Clang static checker(scan-build) warning： fs/smb/client/smb2ops.c:1304:2: Attempt to free released memory. 1304 | kfree(ea); | ^~~~~~~~~
There is a double free in such case: 'ea is initialized to NULL' -> 'first successful memory allocation for ea' -> 'something failed, goto seaexit' -> 'first memory release for ea' -> 'goto replayagain' -> 'second goto seaexit before allocate memory for ea' -> 'second memory release for ea resulted in double free'.
Re-initialie 'ea' to NULL near to the replayagain label, it can fix this double free problem.
In the Linux kernel, the following vulnerability has been resolved:
mptcp: pm: fix UaF read in mptcppmnlrmaddrorsubflow
Syzkaller reported this splat:
================================================================== BUG: KASAN: slab-use-after-free in mptcppmnlrmaddrorsubflow+0xb44/0xcc0 net/mptcp/pmnetlink.c:881 Read of size 4 at addr ffff8880569ac858 by task syz.1.2799/14662
CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 Not tainted 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> dumpstack lib/dumpstack.c:94 [inline] dumpstacklvl+0x116/0x1f0 lib/dumpstack.c:120 printaddressdescription mm/kasan/report.c:377 [inline] printreport+0xc3/0x620 mm/kasan/report.c:488 kasanreport+0xd9/0x110 mm/kasan/report.c:601 mptcppmnlrmaddrorsubflow+0xb44/0xcc0 net/mptcp/pmnetlink.c:881 mptcppmnlrmsubflowreceived net/mptcp/pmnetlink.c:914 [inline] mptcpnlremoveidzeroaddress+0x305/0x4a0 net/mptcp/pmnetlink.c:1572 mptcppmnldeladdrdoit+0x5c9/0x770 net/mptcp/pmnetlink.c:1603 genlfamilyrcvmsgdoit+0x202/0x2f0 net/netlink/genetlink.c:1115 genlfamilyrcvmsg net/netlink/genetlink.c:1195 [inline] genlrcvmsg+0x565/0x800 net/netlink/genetlink.c:1210 netlinkrcvskb+0x165/0x410 net/netlink/afnetlink.c:2551 genlrcv+0x28/0x40 net/netlink/genetlink.c:1219 netlinkunicastkernel net/netlink/afnetlink.c:1331 [inline] netlinkunicast+0x53c/0x7f0 net/netlink/afnetlink.c:1357 netlinksendmsg+0x8b8/0xd70 net/netlink/afnetlink.c:1901 socksendmsgnosec net/socket.c:729 [inline] socksendmsg net/socket.c:744 [inline] syssendmsg+0x9ae/0xb40 net/socket.c:2607 syssendmsg+0x135/0x1e0 net/socket.c:2661 syssendmsg+0x117/0x1f0 net/socket.c:2690 dosyscall32irqson arch/x86/entry/common.c:165 [inline] dofastsyscall32+0x73/0x120 arch/x86/entry/common.c:386 dofastsyscall32+0x32/0x80 arch/x86/entry/common.c:411 entrySYSENTERcompatafterhwframe+0x84/0x8e RIP: 0023:0xf7fe4579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f574556c EFLAGS: 00000296 ORIGRAX: 0000000000000172 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000020000140 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK>
Allocated by task 5387: kasansavestack+0x33/0x60 mm/kasan/common.c:47 kasansavetrack+0x14/0x30 mm/kasan/common.c:68 poisonkmallocredzone mm/kasan/common.c:377 [inline] kasankmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmallocnoprof include/linux/slab.h:878 [inline] kzallocnoprof include/linux/slab.h:1014 [inline] subflowcreatectx+0x87/0x2a0 net/mptcp/subflow.c:1803 subflowulpinit+0xc3/0x4d0 net/mptcp/subflow.c:1956 tcpsetulp net/ipv4/tcpulp.c:146 [inline] tcpsetulp+0x326/0x7f0 net/ipv4/tcpulp.c:167 mptcpsubflowcreatesocket+0x4ae/0x10a0 net/mptcp/subflow.c:1764 mptcpsubflowconnect+0x3cc/0x1490 net/mptcp/subflow.c:1592 mptcppmcreatesubfloworsignaladdr+0xbda/0x23a0 net/mptcp/pmnetlink.c:642 mptcppmnlfullyestablished net/mptcp/pmnetlink.c:650 [inline] mptcppmnlwork+0x3a1/0x4f0 net/mptcp/pmnetlink.c:943 mptcpworker+0x15a/0x1240 net/mptcp/protocol.c:2777 processonework+0x958/0x1b30 kernel/workqueue.c:3229 processscheduledworks kernel/workqueue.c:3310 [inline] workerthread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 retfromfork+0x45/0x80 arch/x86/ke ---truncated---