ghsa-fp29-5f65-3vm6
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: fix double free in 'hci_discovery_filter_clear()'
Function 'hci_discovery_filter_clear()' frees 'uuids' array and then sets it to NULL. There is a tiny chance of the following race:
'hci_cmd_sync_work()'
'update_passive_scan_sync()'
'hci_update_passive_scan_sync()'
'hci_discovery_filter_clear()'
kfree(uuids);
<-------------------------preempted-------------------------------->
'start_service_discovery()'
'hci_discovery_filter_clear()'
kfree(uuids); // DOUBLE FREE
<-------------------------preempted-------------------------------->
uuids = NULL;
To fix it let's add locking around 'kfree()' call and NULL pointer assignment. Otherwise the following backtrace fires:
[ ] ------------[ cut here ]------------ [ ] kernel BUG at mm/slub.c:547! [ ] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP [ ] CPU: 3 UID: 0 PID: 246 Comm: bluetoothd Tainted: G O 6.12.19-kernel #1 [ ] Tainted: [O]=OOT_MODULE [ ] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ ] pc : __slab_free+0xf8/0x348 [ ] lr : __slab_free+0x48/0x348 ... [ ] Call trace: [ ] __slab_free+0xf8/0x348 [ ] kfree+0x164/0x27c [ ] start_service_discovery+0x1d0/0x2c0 [ ] hci_sock_sendmsg+0x518/0x924 [ ] __sock_sendmsg+0x54/0x60 [ ] sock_write_iter+0x98/0xf8 [ ] do_iter_readv_writev+0xe4/0x1c8 [ ] vfs_writev+0x128/0x2b0 [ ] do_writev+0xfc/0x118 [ ] __arm64_sys_writev+0x20/0x2c [ ] invoke_syscall+0x68/0xf0 [ ] el0_svc_common.constprop.0+0x40/0xe0 [ ] do_el0_svc+0x1c/0x28 [ ] el0_svc+0x30/0xd0 [ ] el0t_64_sync_handler+0x100/0x12c [ ] el0t_64_sync+0x194/0x198 [ ] Code: 8b0002e6 eb17031f 54fffbe1 d503201f (d4210000) [ ] ---[ end trace 0000000000000000 ]---
{
"affected": [],
"aliases": [
"CVE-2025-38593"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-19T17:15:37Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix double free in \u0027hci_discovery_filter_clear()\u0027\n\nFunction \u0027hci_discovery_filter_clear()\u0027 frees \u0027uuids\u0027 array and then\nsets it to NULL. There is a tiny chance of the following race:\n\n\u0027hci_cmd_sync_work()\u0027\n\n \u0027update_passive_scan_sync()\u0027\n\n \u0027hci_update_passive_scan_sync()\u0027\n\n \u0027hci_discovery_filter_clear()\u0027\n kfree(uuids);\n\n \u003c-------------------------preempted--------------------------------\u003e\n \u0027start_service_discovery()\u0027\n\n \u0027hci_discovery_filter_clear()\u0027\n kfree(uuids); // DOUBLE FREE\n\n \u003c-------------------------preempted--------------------------------\u003e\n\n uuids = NULL;\n\nTo fix it let\u0027s add locking around \u0027kfree()\u0027 call and NULL pointer\nassignment. Otherwise the following backtrace fires:\n\n[ ] ------------[ cut here ]------------\n[ ] kernel BUG at mm/slub.c:547!\n[ ] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP\n[ ] CPU: 3 UID: 0 PID: 246 Comm: bluetoothd Tainted: G O 6.12.19-kernel #1\n[ ] Tainted: [O]=OOT_MODULE\n[ ] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n[ ] pc : __slab_free+0xf8/0x348\n[ ] lr : __slab_free+0x48/0x348\n...\n[ ] Call trace:\n[ ] __slab_free+0xf8/0x348\n[ ] kfree+0x164/0x27c\n[ ] start_service_discovery+0x1d0/0x2c0\n[ ] hci_sock_sendmsg+0x518/0x924\n[ ] __sock_sendmsg+0x54/0x60\n[ ] sock_write_iter+0x98/0xf8\n[ ] do_iter_readv_writev+0xe4/0x1c8\n[ ] vfs_writev+0x128/0x2b0\n[ ] do_writev+0xfc/0x118\n[ ] __arm64_sys_writev+0x20/0x2c\n[ ] invoke_syscall+0x68/0xf0\n[ ] el0_svc_common.constprop.0+0x40/0xe0\n[ ] do_el0_svc+0x1c/0x28\n[ ] el0_svc+0x30/0xd0\n[ ] el0t_64_sync_handler+0x100/0x12c\n[ ] el0t_64_sync+0x194/0x198\n[ ] Code: 8b0002e6 eb17031f 54fffbe1 d503201f (d4210000)\n[ ] ---[ end trace 0000000000000000 ]---",
"id": "GHSA-fp29-5f65-3vm6",
"modified": "2025-08-19T18:31:33Z",
"published": "2025-08-19T18:31:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38593"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/16852eccbdfaf41a666705e3f8be55cf2864c5ca"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2935e556850e9c94d7a00adf14d3cd7fe406ac03"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a351ff6b8ecca4229afaa0d98042bead8de64799"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f8069f34c4c976786ded97498012225af87435d7"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.