In the Linux kernel, the following vulnerability has been resolved:
md: fix resync softlockup when bitmap size is less than array size
Is is reported that for dm-raid10, lvextend + lvchange --syncaction will
trigger following softlockup:
kernel:watchdog: BUG: soft lockup - CPU#3 stuck for 26s! [mdX_resync:6976]
CPU: 7 PID: 3588 Comm: mdX_resync Kdump: loaded Not tainted 6.9.0-rc4-next-20240419 #1
RIP: 0010:_raw_spin_unlock_irq+0x13/0x30
Call Trace:
<TASK>
md_bitmap_start_sync+0x6b/0xf0
raid10_sync_request+0x25c/0x1b40 [raid10]
md_do_sync+0x64b/0x1020
md_thread+0xa7/0x170
kthread+0xcf/0x100
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1a/0x30
And the detailed process is as follows:
md_do_sync
j = mddev->resync_min
while (j < max_sectors)
sectors = raid10_sync_request(mddev, j, &skipped)
if (!md_bitmap_start_sync(…, &sync_blocks))
// md_bitmap_start_sync set sync_blocks to 0
return sync_blocks + sectors_skippe;
// sectors = 0;
j += sectors;
// j never change
Root cause is that commit 301867b1c168 (“md/raid10: check
slab-out-of-bounds in md_bitmap_get_counter”) return early from
md_bitmap_get_counter(), without setting returned blocks.
Fix this problem by always set returned blocks from
md_bitmap_get_counter"(), as it used to be.
Noted that this patch just fix the softlockup problem in kernel, the
case that bitmap size doesn’t match array size still need to be fixed.
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/md/md-bitmap.c"
],
"versions": [
{
"version": "374fb914304d",
"lessThan": "d4b9c764d48f",
"status": "affected",
"versionType": "git"
},
{
"version": "b0b971fe7d61",
"lessThan": "43771597feba",
"status": "affected",
"versionType": "git"
},
{
"version": "39fa14e824ac",
"lessThan": "3f5b73ef8fd6",
"status": "affected",
"versionType": "git"
},
{
"version": "a134dd582c0d",
"lessThan": "69296914bfd5",
"status": "affected",
"versionType": "git"
},
{
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"lessThan": "71e8e4f288e7",
"status": "affected",
"versionType": "git"
},
{
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"lessThan": "c9566b812c8f",
"status": "affected",
"versionType": "git"
},
{
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"status": "affected",
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},
{
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"lessThan": "8bbc71315e0a",
"status": "affected",
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},
{
"version": "301867b1c168",
"lessThan": "f0e729af2eb6",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/md/md-bitmap.c"
],
"versions": [
{
"version": "6.5",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.5",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.316",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.278",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.219",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.161",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.93",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.33",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.8.12",
"lessThanOrEqual": "6.8.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.9.3",
"lessThanOrEqual": "6.9.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.10",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/3f5b73ef8fd6268cbc968b308d8eafe56fda97f3
git.kernel.org/stable/c/43771597feba89a839c5f893716df88ae5c237ce
git.kernel.org/stable/c/5817f43ae1a118855676f57ef7ab50e37eac7482
git.kernel.org/stable/c/69296914bfd508c85935bf5f711cad9b0fe78492
git.kernel.org/stable/c/71e8e4f288e74a896b6d9cd194f3bab12bd7a10f
git.kernel.org/stable/c/8bbc71315e0ae4bb7e37f8d43b915e1cb01a481b
git.kernel.org/stable/c/c9566b812c8f66160466cc1e29df6d3646add0b1
git.kernel.org/stable/c/d4b9c764d48fa41caa24cfb4275f3aa9fb4bd798
git.kernel.org/stable/c/f0e729af2eb6bee9eb58c4df1087f14ebaefe26b