In the Linux kernel, the following vulnerability has been resolved:
ata: libata-core: Fix null pointer dereference on error
If the ataportalloc() call in atahostalloc() fails, atahostrelease() will get called.
However, the code in atahostrelease() tries to free ata_port struct members unconditionally, which can lead to the following:
BUG: unable to handle page fault for address: 0000000000003990 PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 PID: 594 Comm: (udev-worker) Not tainted 6.10.0-rc5 #44 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:atahostrelease.cold+0x2f/0x6e [libata] Code: e4 4d 63 f4 44 89 e2 48 c7 c6 90 ad 32 c0 48 c7 c7 d0 70 33 c0 49 83 c6 0e 41 RSP: 0018:ffffc90000ebb968 EFLAGS: 00010246 RAX: 0000000000000041 RBX: ffff88810fb52e78 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88813b3218c0 RDI: ffff88813b3218c0 RBP: ffff88810fb52e40 R08: 0000000000000000 R09: 6c65725f74736f68 R10: ffffc90000ebb738 R11: 73692033203a746e R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000011 R15: 0000000000000006 FS: 00007f6cc55b9980(0000) GS:ffff88813b300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000003990 CR3: 00000001122a2000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? _diebody.cold+0x19/0x27 ? pagefaultoops+0x15a/0x2f0 ? excpagefault+0x7e/0x180 ? asmexcpagefault+0x26/0x30 ? atahostrelease.cold+0x2f/0x6e [libata] ? atahostrelease.cold+0x2f/0x6e [libata] releasenodes+0x35/0xb0 devresreleasegroup+0x113/0x140 atahostalloc+0xed/0x120 [libata] atahostallocpinfo+0x14/0xa0 [libata] ahciinit_one+0x6c9/0xd20 [ahci]
Do not access ata_port struct members unconditionally.