On 10/07/2024 19:46, Usama Arif wrote:
>
>
> On 10/07/2024 13:29, Usama Arif wrote:
>>
>>
>> On 10/07/2024 05:51, kernel test robot wrote:
>>>
>>>
>>> Hello,
>>>
>>> kernel test robot noticed "WARNING:at_mm/slub.c:#free_large_kmalloc" on:
>>>
>>> commit: 47325a5c88c5ee373c973e47c27c7dadcfe88a32 ("mm-store-zero-pages-to-be-swapped-out-in-a-bitmap-v8")
>>> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>>>
>>> [test failed on linux-next/master 82d01fe6ee52086035b201cfa1410a3b04384257]
>>>
>>> in testcase: ltp
>>> version: ltp-x86_64-14c1f76-1_20240706
>>> with following parameters:
>>>
>>> test: commands
>>>
>>>
>>>
>>> compiler: gcc-13
>>> test machine: 8 threads 1 sockets Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz (Ivy Bridge) with 16G memory
>>>
>>> (please refer to attached dmesg/kmsg for entire log/backtrace)
>>>
>>>
>>>
>>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>>> the same patch/commit), kindly add following tags
>>> | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
>>> | Closes: https://lore.kernel.org/oe-lkp/202407101031.c6c3c651-lkp@xxxxxxxxx
>>>
>>>
>>> The kernel config and materials to reproduce are available at:
>>> https://download.01.org/0day-ci/archive/20240710/202407101031.c6c3c651-lkp@xxxxxxxxx
>>>
>>>
>>>
>>> kern :warn : [ 455.633948] Swap area shorter than signature indicates
>>> kern :warn : [ 455.634133] ------------[ cut here ]------------
>>> kern :warn : [ 455.634268] WARNING: CPU: 3 PID: 8129 at mm/slub.c:4538 free_large_kmalloc+0x93/0xe0
>>> kern :warn : [ 455.635173] Modules linked in: msdos minix vfat fat xfs ext2 netconsole btrfs blake2b_generic xor zstd_compress raid6_pq libcrc32c intel_rapl_msr intel_rapl_common sd_mod x86_pkg_temp_thermal t10_pi intel_powerclamp coretemp crc64_rocksoft_generic crc64_rocksoft crc64 kvm_intel sg ipmi_devintf ipmi_msghandler i915 kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel sha512_ssse3 drm_buddy intel_gtt firewire_ohci rapl mxm_wmi intel_cstate drm_display_helper firewire_core ahci libahci crc_itu_t i2c_i801 intel_uncore ttm libata drm_kms_helper i2c_smbus lpc_ich video wmi binfmt_misc drm loop fuse dm_mod ip_tables
>>> kern :warn : [ 455.636742] CPU: 3 PID: 8129 Comm: swapon Not tainted 6.10.0-rc6-00357-g47325a5c88c5 #1
>>> kern :warn : [ 455.636935] Hardware name: /DZ77BH-55K, BIOS BHZ7710H.86A.0097.2012.1228.1346 12/28/2012
>>> kern :warn : [ 455.637127] RIP: 0010:free_large_kmalloc+0x93/0xe0
>>> kern :warn : [ 455.637267] Code: 00 41 f7 c4 00 02 00 00 74 01 fb f0 ff 4b 34 74 0b 5b 5d 41 5c 41 5d c3 cc cc cc cc 48 89 df 5b 5d 41 5c 41 5d e9 8d 3f eb ff <0f> 0b 80 3d 14 d8 06 04 00 74 1c 48 89 ef e8 ea b0 1d 02 48 8b 74
>>> kern :warn : [ 455.637951] RSP: 0018:ffffc9000247fdd8 EFLAGS: 00010246
>>> kern :warn : [ 455.638098] RAX: 0017ffffc0000000 RBX: ffffea00055cf900 RCX: 0000000000000000
>>> kern :warn : [ 455.638273] RDX: ffffea0005bb6508 RSI: ffff8881573e4000 RDI: ffffea00055cf900
>>> kern :warn : [ 455.638505] RBP: ffff8881573e4000 R08: 0000000000000001 R09: fffff5200048ffb5
>>> kern :warn : [ 455.638679] R10: 0000000000000003 R11: 0000000000000001 R12: ffff8881ee6b2c28
>>> kern :warn : [ 455.638853] R13: ffff8881393c7890 R14: 00000000ffffffea R15: ffff8881393c7800
>>> kern :warn : [ 455.639028] FS: 00007fa00e70c840(0000) GS:ffff88833c580000(0000) knlGS:0000000000000000
>>> kern :warn : [ 455.639218] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> kern :warn : [ 455.639424] CR2: 00005624b13e8000 CR3: 00000003df01e002 CR4: 00000000001706f0
>>> kern :warn : [ 455.639600] Call Trace:
>>> kern :warn : [ 455.639695] <TASK>
>>> kern :warn : [ 455.639787] ? __warn+0xcc/0x260
>>> kern :warn : [ 455.639900] ? free_large_kmalloc+0x93/0xe0
>>> kern :warn : [ 455.640025] ? report_bug+0x261/0x2c0
>>> kern :warn : [ 455.640141] ? handle_bug+0x6d/0x90
>>> kern :warn : [ 455.640254] ? exc_invalid_op+0x17/0x40
>>> kern :warn : [ 455.640428] ? asm_exc_invalid_op+0x1a/0x20
>>> kern :warn : [ 455.640555] ? free_large_kmalloc+0x93/0xe0
>>> kern :warn : [ 455.640679] __do_sys_swapon+0xaf3/0x1ea0
>>> kern :warn : [ 455.640806] ? poison_slab_object+0xc5/0x170
>>> kern :warn : [ 455.640934] ? __pfx___do_sys_swapon+0x10/0x10
>>> kern :warn : [ 455.641063] ? __x64_sys_close+0x7c/0xd0
>>> kern :warn : [ 455.641184] ? kmem_cache_free+0xd5/0x3e0
>>> kern :warn : [ 455.641307] do_syscall_64+0x5f/0x170
>>> kern :warn : [ 455.641489] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>>> kern :warn : [ 455.641629] RIP: 0033:0x7fa00e8d7f97
>>> kern :warn : [ 455.641746] Code: 73 01 c3 48 8b 0d 69 2e 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a7 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 39 2e 0d 00 f7 d8 64 89 01 48
>>> kern :warn : [ 455.642117] RSP: 002b:00007ffc063cb6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a7
>>> kern :warn : [ 455.642302] RAX: ffffffffffffffda RBX: 00005624b13d89a0 RCX: 00007fa00e8d7f97
>>> kern :warn : [ 455.642535] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005624b13d89a0
>>> kern :warn : [ 455.642709] RBP: 0000000000000000 R08: 0000000000000ff6 R09: 0000000000001000
>>> kern :warn : [ 455.642882] R10: 4e45505355533253 R11: 0000000000000246 R12: 00007ffc063cb91c
>>> kern :warn : [ 455.643056] R13: 00000000ffffffff R14: 0000000012c00000 R15: 00005624b13d95d0
>>> kern :warn : [ 455.643231] </TASK>
>>> kern :warn : [ 455.643321] ---[ end trace 0000000000000000 ]---
>>> kern :warn : [ 455.643507] object pointer: 0x000000003fde23f4
>>> kern :err : [ 455.643635] ==================================================================
>>> kern :err : [ 455.643807] BUG: KASAN: double-free in __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.643978] Free of addr ffff8881573e4000 by task swapon/8129
>>>
>>> kern :err : [ 455.644198] CPU: 3 PID: 8129 Comm: swapon Tainted: G W 6.10.0-rc6-00357-g47325a5c88c5 #1
>>> kern :err : [ 455.644406] Hardware name: /DZ77BH-55K, BIOS BHZ7710H.86A.0097.2012.1228.1346 12/28/2012
>>> kern :err : [ 455.644590] Call Trace:
>>> kern :err : [ 455.644681] <TASK>
>>> kern :err : [ 455.644768] dump_stack_lvl+0x53/0x70
>>> kern :err : [ 455.644883] print_address_description+0x30/0x410
>>> kern :err : [ 455.645033] ? __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.645158] print_report+0xb9/0x2b0
>>> kern :err : [ 455.645275] ? __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.645397] ? kasan_addr_to_slab+0xd/0xb0
>>> kern :err : [ 455.645516] ? __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.645639] kasan_report_invalid_free+0x94/0xc0
>>> kern :err : [ 455.645769] ? __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.645891] free_large_kmalloc+0xb8/0xe0
>>> kern :err : [ 455.646010] __do_sys_swapon+0xaf3/0x1ea0
>>> kern :err : [ 455.646130] ? poison_slab_object+0xc5/0x170
>>> kern :err : [ 455.646254] ? __pfx___do_sys_swapon+0x10/0x10
>>> kern :err : [ 455.646379] ? __x64_sys_close+0x7c/0xd0
>>> kern :err : [ 455.646498] ? kmem_cache_free+0xd5/0x3e0
>>> kern :err : [ 455.646619] do_syscall_64+0x5f/0x170
>>> kern :err : [ 455.646735] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>>> kern :err : [ 455.646871] RIP: 0033:0x7fa00e8d7f97
>>> kern :err : [ 455.646985] Code: 73 01 c3 48 8b 0d 69 2e 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a7 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 39 2e 0d 00 f7 d8 64 89 01 48
>>> kern :err : [ 455.647343] RSP: 002b:00007ffc063cb6e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a7
>>> kern :err : [ 455.647521] RAX: ffffffffffffffda RBX: 00005624b13d89a0 RCX: 00007fa00e8d7f97
>>> kern :err : [ 455.647692] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005624b13d89a0
>>> kern :err : [ 455.647863] RBP: 0000000000000000 R08: 0000000000000ff6 R09: 0000000000001000
>>> kern :err : [ 455.648036] R10: 4e45505355533253 R11: 0000000000000246 R12: 00007ffc063cb91c
>>> kern :err : [ 455.648208] R13: 00000000ffffffff R14: 0000000012c00000 R15: 00005624b13d95d0
>>> kern :err : [ 455.648387] </TASK>
>>>
>>> kern :err : [ 455.648549] The buggy address belongs to the physical page:
>>> kern :warn : [ 455.648692] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881573e5b30 pfn:0x1573e4
>>> kern :warn : [ 455.648902] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
>>> kern :warn : [ 455.649065] raw: 0017ffffc0000000 ffffea0005bb6508 ffff88833c7cb600 0000000000000000
>>> kern :warn : [ 455.649249] raw: ffff8881573e5b30 0000000000000000 00000000ffffffff 0000000000000000
>>> kern :warn : [ 455.649430] page dumped because: kasan: bad access detected
>>>
>>> kern :err : [ 455.649647] Memory state around the buggy address:
>>> kern :err : [ 455.649777] ffff8881573e3f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>>> kern :err : [ 455.649945] ffff8881573e3f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>>> kern :err : [ 455.650115] >ffff8881573e4000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>>> kern :err : [ 455.650286] ^
>>> kern :err : [ 455.650392] ffff8881573e4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>>> kern :err : [ 455.650563] ffff8881573e4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>>> kern :err : [ 455.650733] ==================================================================
>>> kern :warn : [ 455.650954] Disabling lock debugging due to kernel taint
>>> user :notice: [ 455.655806] mkswap01 3 TINFO: Can not do swapon on /dev/loop0.
>>>
>>>
>>>
>>
>>
>> I believe the below diff should solve the warning and double-free. Could this be folded into the patch?
>>
>
> Eventhough not needed, good to set it to NULL in swapoff as well. Next patch has been tested with the LKP test that gives the warning. Thanks.
>
>
Johannes pointed out that we can just keep it simple and set it to NULL after kvfree(p->zeromap). This would be the patch with proper commit message and kernel test robot tags:
commit 63f8e7aae47042d14a24f14997ae916df7433358 (HEAD)
Author: Usama Arif <usamaarif642@xxxxxxxxx>
Date: Wed Jul 10 18:37:57 2024 +0100
mm: set p->zeromap to NULL after freeing it
alloc_swap_info can reuse swap_info_struct from previously
used swap. Reset p->zeromap to NULL so that its not set to
a corrupted pointer from previous swap.
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-lkp/202407101031.c6c3c651-lkp@xxxxxxxxx
Signed-off-by: Usama Arif <usamaarif642@xxxxxxxxx>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index e263511dbb6e..1ee83fcf66ee 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2654,6 +2654,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
p->cluster_next_cpu = NULL;
vfree(swap_map);
kvfree(p->zeromap);
+ p->zeromap = NULL;
kvfree(cluster_info);
/* Destroy swap account information */
swap_cgroup_swapoff(p->type);
@@ -3346,6 +3347,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
spin_unlock(&swap_lock);
vfree(swap_map);
kvfree(p->zeromap);
+ p->zeromap = NULL;
kvfree(cluster_info);
if (inced_nr_rotate_swap)
atomic_dec(&nr_rotate_swap);
