On 6/27/24 03:00, Niklas Cassel wrote:
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: 633273a3ed1c ("libata-pmp: hook PMP support and enable it") Cc: stable@vger.kernel.org Signed-off-by: Niklas Cassel cassel@kernel.org
Looks good, with a nit below. This should be queued as soon as possible as a 6.10 fix patch.
Reviewed-by: Damien Le Moal dlemoal@kernel.org
drivers/ata/libata-core.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index e1bf8a19b3c8..88e32f638f33 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5518,10 +5518,12 @@ static void ata_host_release(struct kref *kref) for (i = 0; i < host->n_ports; i++) { struct ata_port *ap = host->ports[i];
kfree(ap->pmp_link);kfree(ap->slave_link);kfree(ap->ncq_sense_buf);kfree(ap);
if (ap) {kfree(ap->pmp_link);kfree(ap->slave_link);kfree(ap->ncq_sense_buf);kfree(ap);}
Nit: this line can go inside the if as well. Or even better: reverse the if condition and continue to ignore NULL ports.
for (i = 0; i < host->n_ports; i++) { struct ata_port *ap = host->ports[i];
if (!ap) continue;
kfree(ap->pmp_link); kfree(ap->slave_link); kfree(ap->ncq_sense_buf); kfree(ap); host->ports[i] = NULL; }