If e.g. the ata_port_alloc() call in ata_host_alloc() fails, we will jump to the err_out label, which will call devres_release_group(). devres_release_group() will trigger a call to ata_host_release(). ata_host_release() calls kfree(host), so executing the kfree(host) in ata_host_alloc() will lead to a double free:
kernel BUG at mm/slub.c:553! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 11 PID: 599 Comm: (udev-worker) Not tainted 6.10.0-rc5 #47 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:kfree+0x2cf/0x2f0 Code: 5d 41 5e 41 5f 5d e9 80 d6 ff ff 4d 89 f1 41 b8 01 00 00 00 48 89 d9 48 89 da RSP: 0018:ffffc90000f377f0 EFLAGS: 00010246 RAX: ffff888112b1f2c0 RBX: ffff888112b1f2c0 RCX: ffff888112b1f320 RDX: 000000000000400b RSI: ffffffffc02c9de5 RDI: ffff888112b1f2c0 RBP: ffffc90000f37830 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000f37610 R11: 617461203a736b6e R12: ffffea00044ac780 R13: ffff888100046400 R14: ffffffffc02c9de5 R15: 0000000000000006 FS: 00007f2f1cabe980(0000) GS:ffff88813b380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f1c3acf75 CR3: 0000000111724000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x6a/0x90 ? kfree+0x2cf/0x2f0 ? exc_invalid_op+0x50/0x70 ? kfree+0x2cf/0x2f0 ? asm_exc_invalid_op+0x1a/0x20 ? ata_host_alloc+0xf5/0x120 [libata] ? ata_host_alloc+0xf5/0x120 [libata] ? kfree+0x2cf/0x2f0 ata_host_alloc+0xf5/0x120 [libata] ata_host_alloc_pinfo+0x14/0xa0 [libata] ahci_init_one+0x6c9/0xd20 [ahci]
Ensure that we will not call kfree(host) twice, by performing the kfree() only if the devres_open_group() call failed.
Fixes: dafd6c496381 ("libata: ensure host is free'd on error exit paths") Cc: stable@vger.kernel.org Signed-off-by: Niklas Cassel cassel@kernel.org --- drivers/ata/libata-core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 88e32f638f33..c916cbe3e099 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5573,8 +5573,10 @@ struct ata_host *ata_host_alloc(struct device *dev, int max_ports) if (!host) return NULL;
- if (!devres_open_group(dev, NULL, GFP_KERNEL)) - goto err_free; + if (!devres_open_group(dev, NULL, GFP_KERNEL)) { + kfree(host); + return NULL; + }
dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL); if (!dr) @@ -5606,8 +5608,6 @@ struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
err_out: devres_release_group(dev, NULL); - err_free: - kfree(host); return NULL; } EXPORT_SYMBOL_GPL(ata_host_alloc);