| Message ID | 20241107014705.2509463-1-lilingfeng@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | nfsd: set acl_access/acl_default after getting successful | expand |
LGTM Reviewed-by: Yang Erkun <yangerkun@huawei.com> Besides, nfsacld_proc_getacl should fix too. 在 2024/11/7 9:47, Li Lingfeng 写道: > If getting acl_default fails, acl_access and acl_default will be released > simultaneously. However, acl_access will still retain a pointer pointing > to the released posix_acl, which will trigger a WARNING in > nfs3svc_release_getacl like this: > > ------------[ cut here ]------------ > refcount_t: underflow; use-after-free. > WARNING: CPU: 26 PID: 3199 at lib/refcount.c:28 > refcount_warn_saturate+0xb5/0x170 > Modules linked in: > CPU: 26 UID: 0 PID: 3199 Comm: nfsd Not tainted > 6.12.0-rc6-00079-g04ae226af01f-dirty #8 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 1.16.1-2.fc37 04/01/2014 > RIP: 0010:refcount_warn_saturate+0xb5/0x170 > Code: cc cc 0f b6 1d b3 20 a5 03 80 fb 01 0f 87 65 48 d8 00 83 e3 01 75 > e4 48 c7 c7 c0 3b 9b 85 c6 05 97 20 a5 03 01 e8 fb 3e 30 ff <0f> 0b eb > cd 0f b6 1d 8a3 > RSP: 0018:ffffc90008637cd8 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff83904fde > RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88871ed36380 > RBP: ffff888158beeb40 R08: 0000000000000001 R09: fffff520010c6f56 > R10: ffffc90008637ab7 R11: 0000000000000001 R12: 0000000000000001 > R13: ffff888140e77400 R14: ffff888140e77408 R15: ffffffff858b42c0 > FS: 0000000000000000(0000) GS:ffff88871ed00000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000562384d32158 CR3: 000000055cc6a000 CR4: 00000000000006f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > ? refcount_warn_saturate+0xb5/0x170 > ? __warn+0xa5/0x140 > ? refcount_warn_saturate+0xb5/0x170 > ? report_bug+0x1b1/0x1e0 > ? handle_bug+0x53/0xa0 > ? exc_invalid_op+0x17/0x40 > ? asm_exc_invalid_op+0x1a/0x20 > ? tick_nohz_tick_stopped+0x1e/0x40 > ? refcount_warn_saturate+0xb5/0x170 > ? refcount_warn_saturate+0xb5/0x170 > nfs3svc_release_getacl+0xc9/0xe0 > svc_process_common+0x5db/0xb60 > ? __pfx_svc_process_common+0x10/0x10 > ? __rcu_read_unlock+0x69/0xa0 > ? __pfx_nfsd_dispatch+0x10/0x10 > ? svc_xprt_received+0xa1/0x120 > ? xdr_init_decode+0x11d/0x190 > svc_process+0x2a7/0x330 > svc_handle_xprt+0x69d/0x940 > svc_recv+0x180/0x2d0 > nfsd+0x168/0x200 > ? __pfx_nfsd+0x10/0x10 > kthread+0x1a2/0x1e0 > ? kthread+0xf4/0x1e0 > ? __pfx_kthread+0x10/0x10 > ret_from_fork+0x34/0x60 > ? __pfx_kthread+0x10/0x10 > ret_from_fork_asm+0x1a/0x30 > </TASK> > Kernel panic - not syncing: kernel: panic_on_warn set ... > > Clear acl_access/acl_default first and set both of them only when both > ACLs are successfully obtained. > > Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") > Signed-off-by: Li Lingfeng <lilingfeng@huaweicloud.com> > --- > fs/nfsd/nfs3acl.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c > index 5e34e98db969..17579a032a5b 100644 > --- a/fs/nfsd/nfs3acl.c > +++ b/fs/nfsd/nfs3acl.c > @@ -29,10 +29,12 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) > { > struct nfsd3_getaclargs *argp = rqstp->rq_argp; > struct nfsd3_getaclres *resp = rqstp->rq_resp; > - struct posix_acl *acl; > + struct posix_acl *acl = NULL, *dacl = NULL; > struct inode *inode; > svc_fh *fh; > > + resp->acl_access = NULL; > + resp->acl_default = NULL; > fh = fh_copy(&resp->fh, &argp->fh); > resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP); > if (resp->status != nfs_ok) > @@ -56,19 +58,19 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) > resp->status = nfserrno(PTR_ERR(acl)); > goto fail; > } > - resp->acl_access = acl; > } > if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) { > /* Check how Solaris handles requests for the Default ACL > of a non-directory! */ > - acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); > - if (IS_ERR(acl)) { > - resp->status = nfserrno(PTR_ERR(acl)); > + dacl = get_inode_acl(inode, ACL_TYPE_DEFAULT); > + if (IS_ERR(dacl)) { > + resp->status = nfserrno(PTR_ERR(dacl)); > goto fail; > } > - resp->acl_default = acl; > } > > + resp->acl_access = acl; > + resp->acl_default = dacl; > /* resp->acl_{access,default} are released in nfs3svc_release_getacl. */ > out: > return rpc_success;
diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c index 5e34e98db969..17579a032a5b 100644 --- a/fs/nfsd/nfs3acl.c +++ b/fs/nfsd/nfs3acl.c @@ -29,10 +29,12 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) { struct nfsd3_getaclargs *argp = rqstp->rq_argp; struct nfsd3_getaclres *resp = rqstp->rq_resp; - struct posix_acl *acl; + struct posix_acl *acl = NULL, *dacl = NULL; struct inode *inode; svc_fh *fh; + resp->acl_access = NULL; + resp->acl_default = NULL; fh = fh_copy(&resp->fh, &argp->fh); resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP); if (resp->status != nfs_ok) @@ -56,19 +58,19 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) resp->status = nfserrno(PTR_ERR(acl)); goto fail; } - resp->acl_access = acl; } if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) { /* Check how Solaris handles requests for the Default ACL of a non-directory! */ - acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); - if (IS_ERR(acl)) { - resp->status = nfserrno(PTR_ERR(acl)); + dacl = get_inode_acl(inode, ACL_TYPE_DEFAULT); + if (IS_ERR(dacl)) { + resp->status = nfserrno(PTR_ERR(dacl)); goto fail; } - resp->acl_default = acl; } + resp->acl_access = acl; + resp->acl_default = dacl; /* resp->acl_{access,default} are released in nfs3svc_release_getacl. */ out: return rpc_success;
If getting acl_default fails, acl_access and acl_default will be released simultaneously. However, acl_access will still retain a pointer pointing to the released posix_acl, which will trigger a WARNING in nfs3svc_release_getacl like this: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 26 PID: 3199 at lib/refcount.c:28 refcount_warn_saturate+0xb5/0x170 Modules linked in: CPU: 26 UID: 0 PID: 3199 Comm: nfsd Not tainted 6.12.0-rc6-00079-g04ae226af01f-dirty #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb5/0x170 Code: cc cc 0f b6 1d b3 20 a5 03 80 fb 01 0f 87 65 48 d8 00 83 e3 01 75 e4 48 c7 c7 c0 3b 9b 85 c6 05 97 20 a5 03 01 e8 fb 3e 30 ff <0f> 0b eb cd 0f b6 1d 8a3 RSP: 0018:ffffc90008637cd8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff83904fde RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88871ed36380 RBP: ffff888158beeb40 R08: 0000000000000001 R09: fffff520010c6f56 R10: ffffc90008637ab7 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888140e77400 R14: ffff888140e77408 R15: ffffffff858b42c0 FS: 0000000000000000(0000) GS:ffff88871ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562384d32158 CR3: 000000055cc6a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? refcount_warn_saturate+0xb5/0x170 ? __warn+0xa5/0x140 ? refcount_warn_saturate+0xb5/0x170 ? report_bug+0x1b1/0x1e0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x17/0x40 ? asm_exc_invalid_op+0x1a/0x20 ? tick_nohz_tick_stopped+0x1e/0x40 ? refcount_warn_saturate+0xb5/0x170 ? refcount_warn_saturate+0xb5/0x170 nfs3svc_release_getacl+0xc9/0xe0 svc_process_common+0x5db/0xb60 ? __pfx_svc_process_common+0x10/0x10 ? __rcu_read_unlock+0x69/0xa0 ? __pfx_nfsd_dispatch+0x10/0x10 ? svc_xprt_received+0xa1/0x120 ? xdr_init_decode+0x11d/0x190 svc_process+0x2a7/0x330 svc_handle_xprt+0x69d/0x940 svc_recv+0x180/0x2d0 nfsd+0x168/0x200 ? __pfx_nfsd+0x10/0x10 kthread+0x1a2/0x1e0 ? kthread+0xf4/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Kernel panic - not syncing: kernel: panic_on_warn set ... Clear acl_access/acl_default first and set both of them only when both ACLs are successfully obtained. Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") Signed-off-by: Li Lingfeng <lilingfeng@huaweicloud.com> --- fs/nfsd/nfs3acl.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)