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Merged
merged 1 commit into from
Dec 8, 2020
Merged

Use fallible allocs in a few places #47

merged 1 commit into from
Dec 8, 2020

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@alex alex commented Dec 8, 2020

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Nice, thank you!

@alex alex merged commit 4b0e174 into rust Dec 8, 2020
@alex alex deleted the fallible-alloc branch December 8, 2020 04:29
ojeda pushed a commit that referenced this pull request Jan 10, 2022
Hi,

When testing install and uninstall of ipmi_si.ko and ipmi_msghandler.ko,
the system crashed.

The log as follows:
[  141.087026] BUG: unable to handle kernel paging request at ffffffffc09b3a5a
[  141.087241] PGD 8fe4c0d067 P4D 8fe4c0d067 PUD 8fe4c0f067 PMD 103ad89067 PTE 0
[  141.087464] Oops: 0010 [#1] SMP NOPTI
[  141.087580] CPU: 67 PID: 668 Comm: kworker/67:1 Kdump: loaded Not tainted 4.18.0.x86_64 #47
[  141.088009] Workqueue: events 0xffffffffc09b3a40
[  141.088009] RIP: 0010:0xffffffffc09b3a5a
[  141.088009] Code: Bad RIP value.
[  141.088009] RSP: 0018:ffffb9094e2c3e88 EFLAGS: 00010246
[  141.088009] RAX: 0000000000000000 RBX: ffff9abfdb1f04a0 RCX: 0000000000000000
[  141.088009] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
[  141.088009] RBP: 0000000000000000 R08: ffff9abfffee3cb8 R09: 00000000000002e1
[  141.088009] R10: ffffb9094cb73d90 R11: 00000000000f4240 R12: ffff9abfffee8700
[  141.088009] R13: 0000000000000000 R14: ffff9abfdb1f04a0 R15: ffff9abfdb1f04a8
[  141.088009] FS:  0000000000000000(0000) GS:ffff9abfffec0000(0000) knlGS:0000000000000000
[  141.088009] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  141.088009] CR2: ffffffffc09b3a30 CR3: 0000008fe4c0a001 CR4: 00000000007606e0
[  141.088009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  141.088009] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  141.088009] PKRU: 55555554
[  141.088009] Call Trace:
[  141.088009]  ? process_one_work+0x195/0x390
[  141.088009]  ? worker_thread+0x30/0x390
[  141.088009]  ? process_one_work+0x390/0x390
[  141.088009]  ? kthread+0x10d/0x130
[  141.088009]  ? kthread_flush_work_fn+0x10/0x10
[  141.088009]  ? ret_from_fork+0x35/0x40] BUG: unable to handle kernel paging request at ffffffffc0b28a5a
[  200.223240] PGD 97fe00d067 P4D 97fe00d067 PUD 97fe00f067 PMD a580cbf067 PTE 0
[  200.223464] Oops: 0010 [#1] SMP NOPTI
[  200.223579] CPU: 63 PID: 664 Comm: kworker/63:1 Kdump: loaded Not tainted 4.18.0.x86_64 #46
[  200.224008] Workqueue: events 0xffffffffc0b28a40
[  200.224008] RIP: 0010:0xffffffffc0b28a5a
[  200.224008] Code: Bad RIP value.
[  200.224008] RSP: 0018:ffffbf3c8e2a3e88 EFLAGS: 00010246
[  200.224008] RAX: 0000000000000000 RBX: ffffa0799ad6bca0 RCX: 0000000000000000
[  200.224008] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
[  200.224008] RBP: 0000000000000000 R08: ffff9fe43fde3cb8 R09: 00000000000000d5
[  200.224008] R10: ffffbf3c8cb53d90 R11: 00000000000f4240 R12: ffff9fe43fde8700
[  200.224008] R13: 0000000000000000 R14: ffffa0799ad6bca0 R15: ffffa0799ad6bca8
[  200.224008] FS:  0000000000000000(0000) GS:ffff9fe43fdc0000(0000) knlGS:0000000000000000
[  200.224008] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  200.224008] CR2: ffffffffc0b28a30 CR3: 00000097fe00a002 CR4: 00000000007606e0
[  200.224008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  200.224008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  200.224008] PKRU: 55555554
[  200.224008] Call Trace:
[  200.224008]  ? process_one_work+0x195/0x390
[  200.224008]  ? worker_thread+0x30/0x390
[  200.224008]  ? process_one_work+0x390/0x390
[  200.224008]  ? kthread+0x10d/0x130
[  200.224008]  ? kthread_flush_work_fn+0x10/0x10
[  200.224008]  ? ret_from_fork+0x35/0x40
[  200.224008] kernel fault(0x1) notification starting on CPU 63
[  200.224008] kernel fault(0x1) notification finished on CPU 63
[  200.224008] CR2: ffffffffc0b28a5a
[  200.224008] ---[ end trace c82a412d93f57412 ]---

The reason is as follows:
T1: rmmod ipmi_si.
    ->ipmi_unregister_smi()
        -> ipmi_bmc_unregister()
            -> __ipmi_bmc_unregister()
                -> kref_put(&bmc->usecount, cleanup_bmc_device);
                    -> schedule_work(&bmc->remove_work);

T2: rmmod ipmi_msghandler.
    ipmi_msghander module uninstalled, and the module space
    will be freed.

T3: bmc->remove_work doing cleanup the bmc resource.
    -> cleanup_bmc_work()
        -> platform_device_unregister(&bmc->pdev);
            -> platform_device_del(pdev);
                -> device_del(&pdev->dev);
                    -> kobject_uevent(&dev->kobj, KOBJ_REMOVE);
                        -> kobject_uevent_env()
                            -> dev_uevent()
                                -> if (dev->type && dev->type->name)

   'dev->type'(bmc_device_type) pointer space has freed when uninstall
    ipmi_msghander module, 'dev->type->name' cause the system crash.

drivers/char/ipmi/ipmi_msghandler.c:
2820 static const struct device_type bmc_device_type = {
2821         .groups         = bmc_dev_attr_groups,
2822 };

Steps to reproduce:
Add a time delay in cleanup_bmc_work() function,
and uninstall ipmi_si and ipmi_msghandler module.

2910 static void cleanup_bmc_work(struct work_struct *work)
2911 {
2912         struct bmc_device *bmc = container_of(work, struct bmc_device,
2913                                               remove_work);
2914         int id = bmc->pdev.id; /* Unregister overwrites id */
2915
2916         msleep(3000);   <---
2917         platform_device_unregister(&bmc->pdev);
2918         ida_simple_remove(&ipmi_bmc_ida, id);
2919 }

Use 'remove_work_wq' instead of 'system_wq' to solve this issues.

Fixes: b2cfd8a ("ipmi: Rework device id and guid handling to catch changing BMCs")
Signed-off-by: Wu Bo <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Corey Minyard <[email protected]>
ojeda pushed a commit that referenced this pull request Apr 6, 2023
syzbot reported a warning[1] where the bond device itself is a slave and
we try to enslave a non-ethernet device as the first slave which fails
but then in the error path when ether_setup() restores the bond device
it also clears all flags. In my previous fix[2] I restored the
IFF_MASTER flag, but I didn't consider the case that the bond device
itself might also be a slave with IFF_SLAVE set, so we need to restore
that flag as well. Use the bond_ether_setup helper which does the right
thing and restores the bond's flags properly.

Steps to reproduce using a nlmon dev:
 $ ip l add nlmon0 type nlmon
 $ ip l add bond1 type bond
 $ ip l add bond2 type bond
 $ ip l set bond1 master bond2
 $ ip l set dev nlmon0 master bond1
 $ ip -d l sh dev bond1
 22: bond1: <BROADCAST,MULTICAST,MASTER> mtu 1500 qdisc noqueue master bond2 state DOWN mode DEFAULT group default qlen 1000
 (now bond1's IFF_SLAVE flag is gone and we'll hit a warning[3] if we
  try to delete it)

[1] https://syzkaller.appspot.com/bug?id=391c7b1f6522182899efba27d891f1743e8eb3ef
[2] commit 7d5cd2c ("bonding: correctly handle bonding type change on enslave failure")
[3] example warning:
 [   27.008664] bond1: (slave nlmon0): The slave device specified does not support setting the MAC address
 [   27.008692] bond1: (slave nlmon0): Error -95 calling set_mac_address
 [   32.464639] bond1 (unregistering): Released all slaves
 [   32.464685] ------------[ cut here ]------------
 [   32.464686] WARNING: CPU: 1 PID: 2004 at net/core/dev.c:10829 unregister_netdevice_many+0x72a/0x780
 [   32.464694] Modules linked in: br_netfilter bridge bonding virtio_net
 [   32.464699] CPU: 1 PID: 2004 Comm: ip Kdump: loaded Not tainted 5.18.0-rc3+ #47
 [   32.464703] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.1-2.fc37 04/01/2014
 [   32.464704] RIP: 0010:unregister_netdevice_many+0x72a/0x780
 [   32.464707] Code: 99 fd ff ff ba 90 1a 00 00 48 c7 c6 f4 02 66 96 48 c7 c7 20 4d 35 96 c6 05 fa c7 2b 02 01 e8 be 6f 4a 00 0f 0b e9 73 fd ff ff <0f> 0b e9 5f fd ff ff 80 3d e3 c7 2b 02 00 0f 85 3b fd ff ff ba 59
 [   32.464710] RSP: 0018:ffffa006422d7820 EFLAGS: 00010206
 [   32.464712] RAX: ffff8f6e077140a0 RBX: ffffa006422d7888 RCX: 0000000000000000
 [   32.464714] RDX: ffff8f6e12edbe58 RSI: 0000000000000296 RDI: ffffffff96d4a520
 [   32.464716] RBP: ffff8f6e07714000 R08: ffffffff96d63600 R09: ffffa006422d7728
 [   32.464717] R10: 0000000000000ec0 R11: ffffffff9698c988 R12: ffff8f6e12edb140
 [   32.464719] R13: dead000000000122 R14: dead000000000100 R15: ffff8f6e12edb140
 [   32.464723] FS:  00007f297c2f1740(0000) GS:ffff8f6e5d900000(0000) knlGS:0000000000000000
 [   32.464725] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [   32.464726] CR2: 00007f297bf1c800 CR3: 00000000115e8000 CR4: 0000000000350ee0
 [   32.464730] Call Trace:
 [   32.464763]  <TASK>
 [   32.464767]  rtnl_dellink+0x13e/0x380
 [   32.464776]  ? cred_has_capability.isra.0+0x68/0x100
 [   32.464780]  ? __rtnl_unlock+0x33/0x60
 [   32.464783]  ? bpf_lsm_capset+0x10/0x10
 [   32.464786]  ? security_capable+0x36/0x50
 [   32.464790]  rtnetlink_rcv_msg+0x14e/0x3b0
 [   32.464792]  ? _copy_to_iter+0xb1/0x790
 [   32.464796]  ? post_alloc_hook+0xa0/0x160
 [   32.464799]  ? rtnl_calcit.isra.0+0x110/0x110
 [   32.464802]  netlink_rcv_skb+0x50/0xf0
 [   32.464806]  netlink_unicast+0x216/0x340
 [   32.464809]  netlink_sendmsg+0x23f/0x480
 [   32.464812]  sock_sendmsg+0x5e/0x60
 [   32.464815]  ____sys_sendmsg+0x22c/0x270
 [   32.464818]  ? import_iovec+0x17/0x20
 [   32.464821]  ? sendmsg_copy_msghdr+0x59/0x90
 [   32.464823]  ? do_set_pte+0xa0/0xe0
 [   32.464828]  ___sys_sendmsg+0x81/0xc0
 [   32.464832]  ? mod_objcg_state+0xc6/0x300
 [   32.464835]  ? refill_obj_stock+0xa9/0x160
 [   32.464838]  ? memcg_slab_free_hook+0x1a5/0x1f0
 [   32.464842]  __sys_sendmsg+0x49/0x80
 [   32.464847]  do_syscall_64+0x3b/0x90
 [   32.464851]  entry_SYSCALL_64_after_hwframe+0x44/0xae
 [   32.464865] RIP: 0033:0x7f297bf2e5e7
 [   32.464868] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
 [   32.464869] RSP: 002b:00007ffd96c824c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 [   32.464872] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f297bf2e5e7
 [   32.464874] RDX: 0000000000000000 RSI: 00007ffd96c82540 RDI: 0000000000000003
 [   32.464875] RBP: 00000000640f19de R08: 0000000000000001 R09: 000000000000007c
 [   32.464876] R10: 00007f297bffabe0 R11: 0000000000000246 R12: 0000000000000001
 [   32.464877] R13: 00007ffd96c82d20 R14: 00007ffd96c82610 R15: 000055bfe38a7020
 [   32.464881]  </TASK>
 [   32.464882] ---[ end trace 0000000000000000 ]---

Fixes: 7d5cd2c ("bonding: correctly handle bonding type change on enslave failure")
Reported-by: [email protected]
Link: https://syzkaller.appspot.com/bug?id=391c7b1f6522182899efba27d891f1743e8eb3ef
Signed-off-by: Nikolay Aleksandrov <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Acked-by: Jonathan Toppins <[email protected]>
Acked-by: Jay Vosburgh <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
ojeda pushed a commit that referenced this pull request Jan 22, 2024
The test_tag test triggers an unhandled page fault:

  # ./test_tag
  [  130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70
  [  130.640501] Oops[#3]:
  [  130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G      D    O       6.7.0-rc4-loong-devel-gb62ab1a397cf #47 61985c1d94084daa2432f771daa45b56b10d8d2a
  [  130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
  [  130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40
  [  130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000
  [  130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000
  [  130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70
  [  130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0
  [  130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0
  [  130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000
  [  130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000
  [  130.641900]    ra: 9000000003139e70 build_body+0x1fcc/0x4988
  [  130.642007]   ERA: 9000000003137f7c build_body+0xd8/0x4988
  [  130.642112]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
  [  130.642261]  PRMD: 00000004 (PPLV0 +PIE -PWE)
  [  130.642353]  EUEN: 00000003 (+FPE +SXE -ASXE -BTE)
  [  130.642458]  ECFG: 00071c1c (LIE=2-4,10-12 VS=7)
  [  130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
  [  130.642658]  BADV: ffff80001b898004
  [  130.642719]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
  [  130.642815] Modules linked in: [last unloaded: bpf_testmod(O)]
  [  130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd)
  [  130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8
  [  130.643213]         0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0
  [  130.643378]         0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000
  [  130.643538]         0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000
  [  130.643685]         00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000
  [  130.643831]         ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000
  [  130.643983]         0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558
  [  130.644131]         0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000
  [  130.644276]         9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc
  [  130.644423]         ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0
  [  130.644572]         ...
  [  130.644629] Call Trace:
  [  130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988
  [  130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec
  [  130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0
  [  130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44
  [  130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588
  [  130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c
  [  130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94
  [  130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158
  [  130.645507]
  [  130.645539] Code: 380839f6  380831f9  28412bae <24000ca6> 004081ad  0014cb50  004083e8  02bff34c  58008e91
  [  130.645729]
  [  130.646418] ---[ end trace 0000000000000000 ]---

On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at
loading a BPF prog with 2039 instructions:

  prog = (struct bpf_prog *)ffff80001b894000
  insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048
  insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page

In the build_insn() function, we are trying to access next instruction
unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next
page and can be not owned by the current process, thus an page fault is
inevitable and then segfault.

So, let's access next instruction only under `dst = imm64` context.

With this fix, we have:

  # ./test_tag
  test_tag: OK (40945 tests)

Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case")
Tested-by: Tiezhu Yang <[email protected]>
Signed-off-by: Hengqi Chen <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
ojeda pushed a commit that referenced this pull request Jul 8, 2024
If e.g. the ata_port_alloc() call in ata_host_alloc() fails, we will jump
to the err_out label, which will call devres_release_group().
devres_release_group() will trigger a call to ata_host_release().
ata_host_release() calls kfree(host), so executing the kfree(host) in
ata_host_alloc() will lead to a double free:

kernel BUG at mm/slub.c:553!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 11 PID: 599 Comm: (udev-worker) Not tainted 6.10.0-rc5 #47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:kfree+0x2cf/0x2f0
Code: 5d 41 5e 41 5f 5d e9 80 d6 ff ff 4d 89 f1 41 b8 01 00 00 00 48 89 d9 48 89 da
RSP: 0018:ffffc90000f377f0 EFLAGS: 00010246
RAX: ffff888112b1f2c0 RBX: ffff888112b1f2c0 RCX: ffff888112b1f320
RDX: 000000000000400b RSI: ffffffffc02c9de5 RDI: ffff888112b1f2c0
RBP: ffffc90000f37830 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000f37610 R11: 617461203a736b6e R12: ffffea00044ac780
R13: ffff888100046400 R14: ffffffffc02c9de5 R15: 0000000000000006
FS:  00007f2f1cabe980(0000) GS:ffff88813b380000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2f1c3acf75 CR3: 0000000111724000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
 <TASK>
 ? __die_body.cold+0x19/0x27
 ? die+0x2e/0x50
 ? do_trap+0xca/0x110
 ? do_error_trap+0x6a/0x90
 ? kfree+0x2cf/0x2f0
 ? exc_invalid_op+0x50/0x70
 ? kfree+0x2cf/0x2f0
 ? asm_exc_invalid_op+0x1a/0x20
 ? ata_host_alloc+0xf5/0x120 [libata]
 ? ata_host_alloc+0xf5/0x120 [libata]
 ? kfree+0x2cf/0x2f0
 ata_host_alloc+0xf5/0x120 [libata]
 ata_host_alloc_pinfo+0x14/0xa0 [libata]
 ahci_init_one+0x6c9/0xd20 [ahci]

Ensure that we will not call kfree(host) twice, by performing the kfree()
only if the devres_open_group() call failed.

Fixes: dafd6c4 ("libata: ensure host is free'd on error exit paths")
Cc: [email protected]
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Niklas Cassel <[email protected]>
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2 participants