• Niklas Cassel's avatar
    ata: libata-core: Fix null pointer dereference on error · 5d92c7c5
    Niklas Cassel authored
    If the ata_port_alloc() call in ata_host_alloc() fails,
    ata_host_release() will get called.
    
    However, the code in ata_host_release() 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:ata_host_release.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>
     ? __die_body.cold+0x19/0x27
     ? page_fault_oops+0x15a/0x2f0
     ? exc_page_fault+0x7e/0x180
     ? asm_exc_page_fault+0x26/0x30
     ? ata_host_release.cold+0x2f/0x6e [libata]
     ? ata_host_release.cold+0x2f/0x6e [libata]
     release_nodes+0x35/0xb0
     devres_release_group+0x113/0x140
     ata_host_alloc+0xed/0x120 [libata]
     ata_host_alloc_pinfo+0x14/0xa0 [libata]
     ahci_init_one+0x6c9/0xd20 [ahci]
    
    Do not access ata_port struct members unconditionally.
    
    Fixes: 633273a3 ("libata-pmp: hook PMP support and enable it")
    Cc: stable@vger.kernel.org
    Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
    Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
    Reviewed-by: default avatarJohn Garry <john.g.garry@oracle.com>
    Link: https://lore.kernel.org/r/20240629124210.181537-7-cassel@kernel.orgSigned-off-by: default avatarNiklas Cassel <cassel@kernel.org>
    5d92c7c5
libata-core.c 171 KB