From f74f960a18f559e683d6a1f5104e43c3ca93ecb8 Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Mon, 18 Sep 2023 16:13:57 -0500 Subject: [PATCH 01/10] OPENAFS-SA-2024-002: viced: Refuse ACLs without '\0' in SRXAFS_StoreACL CVE-2024-10396 Currently, the fileserver treats the ACL given in RXAFS_StoreACL as a string, even though it is technically an AFSOpaque and could be not NUL-terminated. We give the ACL opaque/string to acl_Internalize_pr() to parse, which will run off the end of the allocated buffer if the given ACL does not contain a '\0' character. Usually this will result in a parse error since we'll encounter garbage, but if the partially-garbage ACL happens to parse successfully, some uninitialized data could make it into the stored ACL. In addition, if the given ACL is an opaque of length 0, we'll still give the opaque pointer to acl_Internalize_pr(). In this case, the pointer will point to &memZero, which happens to contain a NUL byte, and so is treated like an empty string (which is not a valid ACL). But the fact that this causes no problems is somewhat a coincidence, and so should also be avoided. To avoid both of these situations, just check if the given ACL string contains a NUL byte. If it doesn't, or if it has length 0, refuse to look at it and abort the call with EINVAL. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15908 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit e15decb318797f1d471588dc669c3e3b26f1b8b3) Change-Id: I0f447310db5a988b21e19bb5158bb564d4ea3d94 Reviewed-on: https://gerrit.openafs.org/15929 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/viced/afsfileprocs.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c index 31ce69a93d..dad2cd35e4 100644 --- a/src/viced/afsfileprocs.c +++ b/src/viced/afsfileprocs.c @@ -3059,6 +3059,36 @@ SRXAFS_StoreData64(struct rx_call * acall, struct AFSFid * Fid, return code; } +/** + * Check if the given ACL blob is okay to use. + * + * If the given ACL is 0-length, or doesn't contain a NUL byte, return an error + * and refuse the process the given ACL. The ACL must contain a NUL byte, + * otherwise ACL-processing code may run off the end of the buffer and process + * uninitialized memory. + * + * If there is any data beyond the NUL byte, just ignore it and return success. + * We won't look at any post-NUL data, but theoretically clients could send + * such an ACL to us, since historically it's been allowed. + * + * @param[in] AccessList The ACL blob to check + * + * @returns errno error code to abort the call with + * @retval 0 ACL is okay to use + */ +static afs_int32 +check_acl(struct AFSOpaque *AccessList) +{ + if (AccessList->AFSOpaque_len == 0) { + return EINVAL; + } + if (memchr(AccessList->AFSOpaque_val, '\0', + AccessList->AFSOpaque_len) == NULL) { + return EINVAL; + } + return 0; +} + afs_int32 SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, struct AFSOpaque * AccessList, @@ -3082,6 +3112,11 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, if ((errorCode = CallPreamble(acall, ACTIVECALL, Fid, &tcon, &thost))) goto Bad_StoreACL; + errorCode = check_acl(AccessList); + if (errorCode != 0) { + goto Bad_StoreACL; + } + /* Get ptr to client data for user Id for logging */ t_client = (struct client *)rx_GetSpecific(tcon, rxcon_client_key); logHostAddr.s_addr = rxr_HostOf(tcon); -- 2.45.2 From a07e50726df09c49dfe7b953c3e49eb98f310c09 Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Mon, 18 Sep 2023 16:14:07 -0500 Subject: [PATCH 02/10] OPENAFS-SA-2024-002: viced: Free ACL on acl_Internalize_pr error CVE-2024-10396 Currently, we don't free 'newACL' if acl_Internalize_pr() fails. If acl_Internalize_pr() has already allocated 'newACL', then the memory associated with newACL will be leaked. This can happen if parsing the given ACL fails at any point after successfully parsing the first couple of lines in the ACL. Change acl_FreeACL() to make freeing a NULL acl a no-op, to make it easier to make sure the acl has been freed. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15909 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit f4dfc2d7183f126bc4a45b5cabc78c3de020925f) Change-Id: If1554aa899542761ec6e6611394f2ee4f9379f22 Reviewed-on: https://gerrit.openafs.org/15930 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/libacl/aclprocs.c | 4 ++++ src/viced/afsfileprocs.c | 20 ++++++++++++++------ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/src/libacl/aclprocs.c b/src/libacl/aclprocs.c index d4c3f8c4c9..cd07e813c9 100644 --- a/src/libacl/aclprocs.c +++ b/src/libacl/aclprocs.c @@ -116,6 +116,10 @@ acl_FreeACL(struct acl_accessList **acl) /* Releases the access list defined by acl. Returns 0 always. */ struct freeListEntry *x; + if (*acl == NULL) { + return 0; + } + x = (struct freeListEntry *) ((char *)*acl - sizeof(struct freeListEntry *) - sizeof(int)); *acl = NULL; diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c index dad2cd35e4..5df4d6c0cb 100644 --- a/src/viced/afsfileprocs.c +++ b/src/viced/afsfileprocs.c @@ -1248,16 +1248,24 @@ RXFetch_AccessList(Vnode * targetptr, Vnode * parentwhentargetnotdir, static afs_int32 RXStore_AccessList(Vnode * targetptr, struct AFSOpaque *AccessList) { - struct acl_accessList *newACL; /* PlaceHolder for new access list */ + int code; + struct acl_accessList *newACL = NULL; if (acl_Internalize_pr(hpr_NameToId, AccessList->AFSOpaque_val, &newACL) - != 0) - return (EINVAL); - if ((newACL->size + 4) > VAclSize(targetptr)) - return (E2BIG); + != 0) { + code = EINVAL; + goto done; + } + if ((newACL->size + 4) > VAclSize(targetptr)) { + code = E2BIG; + goto done; + } memcpy((char *)VVnodeACL(targetptr), (char *)newACL, (int)(newACL->size)); + code = 0; + + done: acl_FreeACL(&newACL); - return (0); + return code; } /*RXStore_AccessList */ -- 2.45.2 From 1e6e813188ecce62eb7af19385d911f63469bdb6 Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Tue, 19 Sep 2023 15:44:08 -0500 Subject: [PATCH 03/10] OPENAFS-SA-2024-002: acl: Do not parse beyond end of ACL CVE-2024-10396 The early parsing code in acl_Internalize_pr() tries to advance 'nextc' to go beyond the first two newlines in the given ACL string. But if the given ACL string has no newlines, or only 1 newline, then 'nextc' will point beyond the end of the ACL string, potentially pointing to garbage. Intuitively, it may look like the ACL string must contain at least 2 newlines because we have sscanf()'d the string with "%d\n%\d". However, whitespace characters in sscanf() are not matched exactly like non-whitespace characters are; a sequence of whitespace characters matches any amount of whitespace (including none). So, a string like "1 2" will be parsed by "%d\n%d\n", but will not contain any newline characters. Usually this should result in a parse error from acl_Internalize_pr(), but if the garbage happens to parse successfully, this could result in unrelated memory getting stored to the ACL. To fix this, don't advance 'nextc' if we're already at the end of the ACL string. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15910 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit 35d218c1d17973c1412ea5dff1e23d9aae50c4c7) Change-Id: I7a7d136676e548adba5fa8d0003b5f8342332a86 Reviewed-on: https://gerrit.openafs.org/15931 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/libacl/aclprocs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/libacl/aclprocs.c b/src/libacl/aclprocs.c index cd07e813c9..ab6b21dac2 100644 --- a/src/libacl/aclprocs.c +++ b/src/libacl/aclprocs.c @@ -264,10 +264,12 @@ acl_Internalize_pr(int (*func)(namelist *names, idlist *ids), char *elist, struc nextc = elist; while (*nextc && *nextc != '\n') nextc++; - nextc++; + if (*nextc != '\0') + nextc++; while (*nextc && *nextc != '\n') nextc++; - nextc++; /* now at the beginning of the entry list */ + if (*nextc != '\0') + nextc++; /* now at the beginning of the entry list */ for (i = 0; i < (*acl)->positive; i++) { int k; if (sscanf(nextc, "%63s\t%d\n", lnames.namelist_val[i], &k) != 2) { -- 2.45.2 From d66caf8c04878724001839317637445708edef2c Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Tue, 19 Sep 2023 15:55:42 -0500 Subject: [PATCH 04/10] OPENAFS-SA-2024-002: acl: Error on missing newlines when parsing ACL CVE-2024-10396 In acl_Internalize_pr(), each line in an ACL granting rights (positive or negative) is sscanf()'d with "%63s\t%d\n", and then we try to advance 'nextc' beyond the next newline character. However, sscanf()'ing "%63s\t%d\n" does not guarantee that there is a newline in the given string. Whitespace characters in sscanf() are not matched exactly, and may match any amount of whitespace (including none at all). For example, a string like "foo 4" may be parsed by sscanf(), but does not contain any newlines. If this happens, strchr(nextc, '\n') will return NULL, and we'll advance 'nextc' to 0x1, causing a segfault when we next try to dereference 'nextc'. To avoid this, check if 'nextc' is NULL after the strchr() call, and return an error if so. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15911 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit 96ab2c6f8a614d597a523b45871c5f64a50a7040) Change-Id: I666dfb2c401410865c1f98d9db1b342b52c8f628 Reviewed-on: https://gerrit.openafs.org/15932 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/libacl/aclprocs.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/libacl/aclprocs.c b/src/libacl/aclprocs.c index ab6b21dac2..fbdfaa6f9c 100644 --- a/src/libacl/aclprocs.c +++ b/src/libacl/aclprocs.c @@ -278,6 +278,10 @@ acl_Internalize_pr(int (*func)(namelist *names, idlist *ids), char *elist, struc } (*acl)->entries[i].rights = k; nextc = strchr(nextc, '\n'); + if (nextc == NULL) { + free(lnames.namelist_val); + return (-1); + } nextc++; /* 1 + index can cast ptr to integer */ } j = i; @@ -290,6 +294,10 @@ acl_Internalize_pr(int (*func)(namelist *names, idlist *ids), char *elist, struc return (-1); } nextc = strchr(nextc, '\n'); + if (nextc == NULL) { + free(lnames.namelist_val); + return (-1); + } nextc++; } lids.idlist_len = 0; -- 2.45.2 From ee020f7cba7d82bc3d4b468210b5052af53c5db5 Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Wed, 21 Aug 2024 00:29:34 -0500 Subject: [PATCH 05/10] OPENAFS-SA-2024-002: viced: Introduce 'rawACL' in StoreACL CVE-2024-10396 Change our StoreACL implementation to refer to the 'AccessList' argument via a new local variable called 'rawACL'. This makes it clearer to users that the data is a string, and makes it easier for future commits to make sure we don't access the 'AccessList' argument in certain situations. Update almost all users in StoreACL to refer to 'rawACL' instead of 'AccessList'. Change the name of 'AccessList' to 'uncheckedACL' to make sure we don't miss any users. Update our check_acl() call to use 'uncheckedACL' (and not 'rawACL'), because it must use an AFSOpaque to check the ACL. Change RXStore_AccessList() and printableACL() to accept a plain char* instead of a struct AFSOpaque. This commit should not incur any noticeable behavior change. Technically printableACL() is changed to run strlen() on the given string, but this should not cause any noticeable change in behavior: This change could cause printableACL() to process less of the string than before, if the string contains a NUL byte before the end of the AFSOpaque buffer. But this doesn't matter, since the all of our code after this treats the ACL as a plain string, and so doesn't look at any data beyond the first NUL. It's not possible for printableACL() to process more data than before, because check_acl() has already checked that the ACL string contains a NUL byte, so we must process AFSOpaque_len bytes or fewer. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15912 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit eb8b93a971c6293cdfbf8cd3d9a6351a8cb76f81) [1.8: printableACL() does not exist in this branch.] Change-Id: I65b518acab26be0bb1854c29e46c90e5fee52d41 Reviewed-on: https://gerrit.openafs.org/15933 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/viced/afsfileprocs.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c index 5df4d6c0cb..77c6165e7b 100644 --- a/src/viced/afsfileprocs.c +++ b/src/viced/afsfileprocs.c @@ -1246,12 +1246,12 @@ RXFetch_AccessList(Vnode * targetptr, Vnode * parentwhentargetnotdir, * the target dir's vnode storage. */ static afs_int32 -RXStore_AccessList(Vnode * targetptr, struct AFSOpaque *AccessList) +RXStore_AccessList(Vnode * targetptr, char *AccessList) { int code; struct acl_accessList *newACL = NULL; - if (acl_Internalize_pr(hpr_NameToId, AccessList->AFSOpaque_val, &newACL) + if (acl_Internalize_pr(hpr_NameToId, AccessList, &newACL) != 0) { code = EINVAL; goto done; @@ -3099,7 +3099,7 @@ check_acl(struct AFSOpaque *AccessList) afs_int32 SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, - struct AFSOpaque * AccessList, + struct AFSOpaque *uncheckedACL, struct AFSFetchStatus * OutStatus, struct AFSVolSync * Sync) { Vnode *targetptr = 0; /* pointer to input fid */ @@ -3114,13 +3114,14 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, struct client *t_client = NULL; /* tmp ptr to client data */ struct in_addr logHostAddr; /* host ip holder for inet_ntoa */ struct fsstats fsstats; + char *rawACL = uncheckedACL->AFSOpaque_val; fsstats_StartOp(&fsstats, FS_STATS_RPCIDX_STOREACL); if ((errorCode = CallPreamble(acall, ACTIVECALL, Fid, &tcon, &thost))) goto Bad_StoreACL; - errorCode = check_acl(AccessList); + errorCode = check_acl(uncheckedACL); if (errorCode != 0) { goto Bad_StoreACL; } @@ -3130,7 +3131,7 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, logHostAddr.s_addr = rxr_HostOf(tcon); ViceLog(1, ("SAFS_StoreACL, Fid = %u.%u.%u, ACL=%s, Host %s:%d, Id %d\n", - Fid->Volume, Fid->Vnode, Fid->Unique, AccessList->AFSOpaque_val, + Fid->Volume, Fid->Vnode, Fid->Unique, rawACL, inet_ntoa(logHostAddr), ntohs(rxr_PortOf(tcon)), t_client->z.ViceId)); FS_LOCK; AFSCallStats.StoreACL++, AFSCallStats.TotalCalls++; @@ -3159,7 +3160,7 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, } /* Build and store the new Access List for the dir */ - if ((errorCode = RXStore_AccessList(targetptr, AccessList))) { + if ((errorCode = RXStore_AccessList(targetptr, rawACL))) { goto Bad_StoreACL; } @@ -3186,7 +3187,7 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, osi_auditU(acall, StoreACLEvent, errorCode, AUD_ID, t_client ? t_client->z.ViceId : 0, - AUD_FID, Fid, AUD_ACL, AccessList->AFSOpaque_val, AUD_END); + AUD_FID, Fid, AUD_ACL, rawACL, AUD_END); return errorCode; } /*SRXAFS_StoreACL */ -- 2.45.2 From bb01d76a2095baa65880bdc5d504e7a198958265 Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Wed, 21 Aug 2024 00:41:49 -0500 Subject: [PATCH 06/10] OPENAFS-SA-2024-002: viced: Avoid unchecked ACL in StoreACL audit log CVE-2024-10396 Currently in SRXAFS_StoreACL, if CallPreamble() or check_acl() fail, we will jump to Bad_StoreACL, which will pass the ACL string from the client to osi_auditU. Since check_acl() hasn't yet checked if the given ACL contains a NUL byte, the ACL may be an unterminated string. If auditing is enabled, this can cause garbage to be logged to the audit log, or cause the fileserver to crash. To avoid this, set 'rawACL' to NULL at first, only setting it to the actual ACL string after check_acl() has succeeded. This ensures that all code accessing 'rawACL' is guaranteed to be using a terminated string. This may mean that we pass a NULL AUD_ACL to osi_auditU. Our auditing code explicitly checks for and handles handles NULL strings, so this is fine. FIXES 135445 Reviewed-on: https://gerrit.openafs.org/15913 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit c9eae1e8b26144063e5d1db23d47ee82c4b9ef3a) Change-Id: Ieda6f910d875c4b5179011e5e93e5694d3f4ce47 Reviewed-on: https://gerrit.openafs.org/15934 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/viced/afsfileprocs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c index 77c6165e7b..5e6655fa26 100644 --- a/src/viced/afsfileprocs.c +++ b/src/viced/afsfileprocs.c @@ -3114,7 +3114,7 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, struct client *t_client = NULL; /* tmp ptr to client data */ struct in_addr logHostAddr; /* host ip holder for inet_ntoa */ struct fsstats fsstats; - char *rawACL = uncheckedACL->AFSOpaque_val; + char *rawACL = NULL; fsstats_StartOp(&fsstats, FS_STATS_RPCIDX_STOREACL); @@ -3125,6 +3125,7 @@ SRXAFS_StoreACL(struct rx_call * acall, struct AFSFid * Fid, if (errorCode != 0) { goto Bad_StoreACL; } + rawACL = uncheckedACL->AFSOpaque_val; /* Get ptr to client data for user Id for logging */ t_client = (struct client *)rx_GetSpecific(tcon, rxcon_client_key); -- 2.45.2 From 64068705b15661a8d4e0b9f9f2ad4aec34ed51a7 Mon Sep 17 00:00:00 2001 From: Benjamin Kaduk Date: Mon, 4 Nov 2024 20:33:16 -0800 Subject: [PATCH 07/10] OPENAFS-SA-2024-002: verify FetchACL returned a valid string CVE-2024-10396 Analogously to how a call to RXAFS_StoreACL() with a malformed ACL string can cause a fileserver to perform invalid memory operations, a malformed ACL string returned in response to a call to RXAFS_FetchACL() can cause a client to perform invalid memory operations. Modify all the in-tree callers of the RPC to verify that the ACL data, which is conveyed as an XDR 'opaque' but whose contents are actually expected to be a string, is a valid C string. If a zero-length opaque or one without a trailing NUL is received, treat that as an error response from the fileserver rather than returning success. The Unix cache manager's pioctl handler already has logic to cope with a zero-length reply by emitting a single NUL byte to userspace. This special-casing seems to have been in place from the original IBM import, though it does so by confusingly "skipping over" a NUL byte already put in place. For historical compatibility, preserve that behavior rather than treating the zero-length reply as an error as we do for the other callers. It seems likely that this location should treat a zero-length reply as an error just as the other call sites do, but that can be done as a later change. Reviewed-on: https://gerrit.openafs.org/15914 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit 0b1ccb0dbc3b7673558eceff3d672971f5bb0197) Change-Id: Ifbce762d76641f08b5fc5e79b4c8dad07c1a135a Reviewed-on: https://gerrit.openafs.org/15935 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/WINNT/afsd/cm_ioctl.c | 4 ++++ src/afs/afs_pioctl.c | 10 ++++++++-- src/libafscp/afscp_acl.c | 6 ++++++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/src/WINNT/afsd/cm_ioctl.c b/src/WINNT/afsd/cm_ioctl.c index ba4530fc8d..48bee6b621 100644 --- a/src/WINNT/afsd/cm_ioctl.c +++ b/src/WINNT/afsd/cm_ioctl.c @@ -447,6 +447,10 @@ cm_IoctlGetACL(cm_ioctl_t *ioctlp, cm_user_t *userp, cm_scache_t *scp, cm_req_t if (code) return code; + /* Ensure the ACL is a string before trying to treat it like one. */ + if (acl.AFSOpaque_len == 0 || memchr(acl.AFSOpaque_val, '\0', + acl.AFSOpaque_len) == NULL) + return CM_ERROR_INVAL; } /* skip over return data */ tlen = (int)strlen(ioctlp->outDatap) + 1; diff --git a/src/afs/afs_pioctl.c b/src/afs/afs_pioctl.c index 172f8aa519..efb884c59e 100644 --- a/src/afs/afs_pioctl.c +++ b/src/afs/afs_pioctl.c @@ -1607,10 +1607,16 @@ DECL_PIOCTL(PGetAcl) SHARED_LOCK, NULL)); if (code == 0) { - if (acl.AFSOpaque_len == 0) + if (acl.AFSOpaque_len == 0) { afs_pd_skip(aout, 1); /* leave the NULL */ - else + + } else if (memchr(acl.AFSOpaque_val, '\0', acl.AFSOpaque_len) == NULL) { + /* Do not return an unterminated ACL string. */ + code = EINVAL; + + } else { afs_pd_skip(aout, acl.AFSOpaque_len); /* Length of the ACL */ + } } return code; } diff --git a/src/libafscp/afscp_acl.c b/src/libafscp/afscp_acl.c index 596d0e436d..9f93271317 100644 --- a/src/libafscp/afscp_acl.c +++ b/src/libafscp/afscp_acl.c @@ -58,6 +58,12 @@ afscp_FetchACL(const struct afscp_venusfid *dir, struct AFSOpaque *acl) code = RXAFS_FetchACL(server->conns[j], &df, acl, &dfst, &vs); if (code >= 0) break; + /* Zero-length or non-string ACLs are malformed. */ + if (acl->AFSOpaque_len == 0 || memchr(acl->AFSOpaque_val, '\0', + acl->AFSOpaque_len) == NULL) { + code = EIO; + break; + } } } if (code >= 0) -- 2.45.2 From a96a3160f5425125588f39f5ac612df3ef9b9a8a Mon Sep 17 00:00:00 2001 From: Benjamin Kaduk Date: Mon, 4 Nov 2024 20:50:50 -0800 Subject: [PATCH 08/10] OPENAFS-SA-2024-002: verify FetchACL returned only a string CVE-2024-10396 Supplement the previous commit by additionally verifying that the returned ACL string occupies the entire XDR opaque, rejecting any values returned that have an internal NUL prior to the end of the opaque. Reviewed-on: https://gerrit.openafs.org/15915 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit 7e13414e8ea995d438cde3e60988225f3ab4cbcd) Change-Id: I107f89e3d8a5c3c5cd67f6296742bfca7cace0e1 Reviewed-on: https://gerrit.openafs.org/15936 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/WINNT/afsd/cm_ioctl.c | 3 +++ src/afs/afs_pioctl.c | 4 ++++ src/libafscp/afscp_acl.c | 4 ++++ 3 files changed, 11 insertions(+) diff --git a/src/WINNT/afsd/cm_ioctl.c b/src/WINNT/afsd/cm_ioctl.c index 48bee6b621..fd7c6adc8a 100644 --- a/src/WINNT/afsd/cm_ioctl.c +++ b/src/WINNT/afsd/cm_ioctl.c @@ -451,6 +451,9 @@ cm_IoctlGetACL(cm_ioctl_t *ioctlp, cm_user_t *userp, cm_scache_t *scp, cm_req_t if (acl.AFSOpaque_len == 0 || memchr(acl.AFSOpaque_val, '\0', acl.AFSOpaque_len) == NULL) return CM_ERROR_INVAL; + /* Reject "strings" with trailing data after the NUL. */ + if (strlen(acl.AFSOpaque_val) + 1 != acl.AFSOpaque_len) + return CM_ERROR_INVAL; } /* skip over return data */ tlen = (int)strlen(ioctlp->outDatap) + 1; diff --git a/src/afs/afs_pioctl.c b/src/afs/afs_pioctl.c index efb884c59e..95202f020c 100644 --- a/src/afs/afs_pioctl.c +++ b/src/afs/afs_pioctl.c @@ -1614,6 +1614,10 @@ DECL_PIOCTL(PGetAcl) /* Do not return an unterminated ACL string. */ code = EINVAL; + } else if (strlen(acl.AFSOpaque_val) + 1 != acl.AFSOpaque_len) { + /* Do not return an ACL string that has data beyond the trailing NUL. */ + code = EINVAL; + } else { afs_pd_skip(aout, acl.AFSOpaque_len); /* Length of the ACL */ } diff --git a/src/libafscp/afscp_acl.c b/src/libafscp/afscp_acl.c index 9f93271317..f9cd3740dc 100644 --- a/src/libafscp/afscp_acl.c +++ b/src/libafscp/afscp_acl.c @@ -64,6 +64,10 @@ afscp_FetchACL(const struct afscp_venusfid *dir, struct AFSOpaque *acl) code = EIO; break; } + if (strlen(acl->AFSOpaque_val) + 1 != acl->AFSOpaque_len) { + code = EIO; + break; + } } } if (code >= 0) -- 2.45.2 From a9ede52673b8c8abbfc2577ac6987a8a5686206f Mon Sep 17 00:00:00 2001 From: Benjamin Kaduk Date: Mon, 4 Nov 2024 20:50:50 -0800 Subject: [PATCH 09/10] OPENAFS-SA-2024-002: make VIOCGETAL consumers stay within string bounds CVE-2024-10396 After the preceding commits, the data returned by the VIOCGETAL pioctl (a RXAFS_FetchAcl wrapper) will safely be NUL-terminated. However, the callers that attempt to parse the ACL string make assumptions that the returned data will be properly formatted, and implement a "skip to next line" functionality (under various names) that blindly increments a char* until it finds a newline character, which can read past the end of even a properly NUL-terminated string if there is not a newline where one is expected. Adjust the various "skip to next line" functionality to keep the current string pointer at the trailing NUL if the end of the string is reached while searching for a newline. Reviewed-on: https://gerrit.openafs.org/15916 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit a4ecb050540528a1bff840ff08d21f99e6ef3fbf) Change-Id: Id2d8c0164cfaa7d03a9e37b29ff58b88cf815483 Reviewed-on: https://gerrit.openafs.org/15937 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/WINNT/afsd/fs_acl.c | 5 +++-- src/kauth/kkids.c | 2 +- src/kauth/test/test_interim_ktc.c | 5 +++-- src/libadmin/client/afs_clientAdmin.c | 6 ++++++ src/sys/rmtsysnet.c | 5 +++-- src/uss/uss_acl.c | 5 +++-- src/venus/fs.c | 5 +++-- 7 files changed, 22 insertions(+), 11 deletions(-) diff --git a/src/WINNT/afsd/fs_acl.c b/src/WINNT/afsd/fs_acl.c index 8012891cd8..351fe05a4f 100644 --- a/src/WINNT/afsd/fs_acl.c +++ b/src/WINNT/afsd/fs_acl.c @@ -81,9 +81,10 @@ PruneList (struct AclEntry **ae, int dfs) static char * SkipLine (char *astr) { - while (*astr !='\n') + while (*astr != '\0' && *astr !='\n') astr++; - astr++; + if (*astr == '\n') + astr++; return astr; } diff --git a/src/kauth/kkids.c b/src/kauth/kkids.c index d5437f152f..ebc4c331e6 100644 --- a/src/kauth/kkids.c +++ b/src/kauth/kkids.c @@ -190,7 +190,7 @@ find_me(char *arg, char *parent_dir) return 1; /* found it */ } -#define SkipLine(str) { while (*str !='\n') str++; str++; } +#define SkipLine(str) do { while (*str != '\0' && *str !='\n') str++; if (*str == '\n') str++; } while(0) /* this function returns TRUE (1) if the file is in AFS, otherwise false (0) */ static int diff --git a/src/kauth/test/test_interim_ktc.c b/src/kauth/test/test_interim_ktc.c index 58cf061fd5..8af9035187 100644 --- a/src/kauth/test/test_interim_ktc.c +++ b/src/kauth/test/test_interim_ktc.c @@ -385,9 +385,10 @@ char * SkipLine(astr) char *astr; { - while (*astr != '\n') + while (*astr != '\0' && *astr != '\n') + astr++; + if (*astr == '\n') astr++; - astr++; return astr; } diff --git a/src/libadmin/client/afs_clientAdmin.c b/src/libadmin/client/afs_clientAdmin.c index d0f61f1063..e4c9a7d426 100644 --- a/src/libadmin/client/afs_clientAdmin.c +++ b/src/libadmin/client/afs_clientAdmin.c @@ -1535,9 +1535,13 @@ afsclient_ACLEntryAdd(const char *directory, const char *user, sscanf(old_acl_string, "%d dfs:%d %1024s", &cur_acl.nplus, &cur_acl.dfs, cur_acl.cell); ptr = strchr(old_acl_string, '\n'); + if (ptr == NULL) + goto fail_afsclient_ACLEntryAdd; ptr++; sscanf(ptr, "%d", &cur_acl.nminus); ptr = strchr(ptr, '\n'); + if (ptr == NULL) + goto fail_afsclient_ACLEntryAdd; ptr++; if (is_dfs == 3) { tst = ADMMISCNODFSACL; @@ -1564,6 +1568,8 @@ afsclient_ACLEntryAdd(const char *directory, const char *user, if (strcmp(cur_user, user)) { ptr = strchr(ptr, '\n'); + if (ptr == NULL) + goto fail_afsclient_ACLEntryAdd; ptr++; sprintf(tmp, "%s %d\n", cur_user, cur_user_acl); strcat(new_acl_string, tmp); diff --git a/src/sys/rmtsysnet.c b/src/sys/rmtsysnet.c index da6b3e64e4..bdb5c0d72a 100644 --- a/src/sys/rmtsysnet.c +++ b/src/sys/rmtsysnet.c @@ -55,9 +55,10 @@ struct ClearToken { char * RSkipLine(char *astr) { - while (*astr != '\n') + while (*astr != '\0' && *astr != '\n') + astr++; + if (*astr == '\n') astr++; - astr++; return astr; } diff --git a/src/uss/uss_acl.c b/src/uss/uss_acl.c index 003eff8b93..b3450ba2b2 100644 --- a/src/uss/uss_acl.c +++ b/src/uss/uss_acl.c @@ -339,9 +339,10 @@ static char * SkipLine(char *a_str) { /*SkipLine */ - while (*a_str != '\n') + while (*a_str != '\0' && *a_str != '\n') + a_str++; + if (*a_str == '\n') a_str++; - a_str++; return (a_str); } /*SkipLine */ diff --git a/src/venus/fs.c b/src/venus/fs.c index ac16bb43b1..32fa73fc33 100644 --- a/src/venus/fs.c +++ b/src/venus/fs.c @@ -553,9 +553,10 @@ PruneList(struct AclEntry **ae, int dfs) static char * SkipLine(char *astr) { - while (*astr != '\n') + while (*astr != '\0' && *astr != '\n') + astr++; + if (*astr == '\n') astr++; - astr++; return astr; } -- 2.45.2 From 21941c0ab2d28fa3a074f46e4d448d518a7c1b8a Mon Sep 17 00:00:00 2001 From: Andrew Deason Date: Tue, 5 Nov 2024 23:40:24 -0600 Subject: [PATCH 10/10] OPENAFS-SA-2024-002: Avoid uninitialized memory when parsing ACLs CVE-2024-10396 Several places in the tree parse ACLs using sscanf() calls that look similar to this: sscanf(str, "%d dfs:%d %s", &nplus, &dfs, cell); sscanf(str, "%100s %d", tname, &trights); Some callers check whether the scanf() returns negative or 0, but some callers do not check the return code at all. If only some of the fields are present in the sscanf()'d string (because, for instance, the ACL is malformed), some of the arguments are left alone, and may be set to garbage if the relevant variable was never initialized. If the parsed ACL is copied to another ACL, this can result in the copied ACL containing uninitialized memory. To avoid this, make sure all of the variables passed to sscanf() and similar calls are initialized before parsing. This commit does not guarantee that the results make sense, but at least the results do not contain uninitialized memory. Reviewed-on: https://gerrit.openafs.org/15917 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk (cherry picked from commit ac602a0a5624b0f0ab04df86f618d09f2a4ad063) Change-Id: I00245c12993683eb3b58d51cf77742f758bac120 Reviewed-on: https://gerrit.openafs.org/15938 Reviewed-by: Benjamin Kaduk Tested-by: Benjamin Kaduk --- src/WINNT/afsd/fs_acl.c | 10 +++++----- src/kauth/kkids.c | 4 ++-- src/kauth/test/test_interim_ktc.c | 10 +++++----- src/libadmin/client/afs_clientAdmin.c | 3 +++ src/sys/rmtsysnet.c | 8 ++++---- src/uss/uss_acl.c | 8 ++++---- src/venus/fs.c | 12 ++++++------ 7 files changed, 29 insertions(+), 26 deletions(-) diff --git a/src/WINNT/afsd/fs_acl.c b/src/WINNT/afsd/fs_acl.c index 351fe05a4f..45218ae3d8 100644 --- a/src/WINNT/afsd/fs_acl.c +++ b/src/WINNT/afsd/fs_acl.c @@ -167,7 +167,7 @@ EmptyAcl(char *astr) struct Acl *tp; int junk; - tp = (struct Acl *)malloc(sizeof (struct Acl)); + tp = (struct Acl *)calloc(sizeof(*tp), 1); assert(tp); tp->nplus = tp->nminus = 0; tp->pluslist = tp->minuslist = 0; @@ -232,9 +232,9 @@ CleanAcl(struct Acl *aa, char *cellname) struct Acl * ParseAcl (char *astr, int astr_size) { - int nplus, nminus, i, trights, ret; + int nplus, nminus, i, trights = 0, ret; size_t len; - char tname[ACL_MAXNAME]; + char tname[ACL_MAXNAME + 1] = ""; struct AclEntry *first, *next, *last, *tl; struct Acl *ta; @@ -281,7 +281,7 @@ ParseAcl (char *astr, int astr_size) if (ret <= 0) goto nplus_err; astr = SkipLine(astr); - tl = (struct AclEntry *) malloc(sizeof (struct AclEntry)); + tl = (struct AclEntry *) calloc(sizeof(*tl), 1); if (tl == NULL) goto nplus_err; if (!first) @@ -309,7 +309,7 @@ ParseAcl (char *astr, int astr_size) if (ret <= 0) goto nminus_err; astr = SkipLine(astr); - tl = (struct AclEntry *) malloc(sizeof (struct AclEntry)); + tl = (struct AclEntry *) calloc(sizeof(*tl), 1); if (tl == NULL) goto nminus_err; if (!first) diff --git a/src/kauth/kkids.c b/src/kauth/kkids.c index ebc4c331e6..7e9043fdd6 100644 --- a/src/kauth/kkids.c +++ b/src/kauth/kkids.c @@ -228,7 +228,7 @@ struct AclEntry { static struct Acl * ParseAcl(char *astr) { - int nplus, nminus, i, trights; + int nplus = 0, nminus = 0, i, trights = 0; char tname[MAXNAME + 1] = ""; struct AclEntry *first, *last, *tl; struct Acl *ta; @@ -237,7 +237,7 @@ ParseAcl(char *astr) sscanf(astr, "%d", &nminus); SkipLine(astr); - ta = malloc(sizeof(struct Acl)); + ta = calloc(sizeof(*ta), 1); ta->nplus = nplus; last = 0; diff --git a/src/kauth/test/test_interim_ktc.c b/src/kauth/test/test_interim_ktc.c index 8af9035187..bc58f8668b 100644 --- a/src/kauth/test/test_interim_ktc.c +++ b/src/kauth/test/test_interim_ktc.c @@ -396,8 +396,8 @@ struct Acl * ParseAcl(astr) char *astr; { - int nplus, nminus, i, trights; - char tname[MAXNAME]; + int nplus = 0, nminus = 0, i, trights = 0; + char tname[MAXNAME + 1] = ""; struct AclEntry *first, *last, *tl; struct Acl *ta; sscanf(astr, "%d", &nplus); @@ -405,7 +405,7 @@ ParseAcl(astr) sscanf(astr, "%d", &nminus); astr = SkipLine(astr); - ta = malloc(sizeof(struct Acl)); + ta = calloc(sizeof(*ta), 1); ta->nplus = nplus; ta->nminus = nminus; @@ -414,7 +414,7 @@ ParseAcl(astr) for (i = 0; i < nplus; i++) { sscanf(astr, "%100s %d", tname, &trights); astr = SkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); @@ -431,7 +431,7 @@ ParseAcl(astr) for (i = 0; i < nminus; i++) { sscanf(astr, "%100s %d", tname, &trights); astr = SkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); diff --git a/src/libadmin/client/afs_clientAdmin.c b/src/libadmin/client/afs_clientAdmin.c index e4c9a7d426..b485f48e7c 100644 --- a/src/libadmin/client/afs_clientAdmin.c +++ b/src/libadmin/client/afs_clientAdmin.c @@ -1435,6 +1435,9 @@ afsclient_ACLEntryAdd(const char *directory, const char *user, char tmp[64 + 35]; int is_dfs; + memset(&cur_acl, 0, sizeof(cur_acl)); + memset(cur_user, 0, sizeof(cur_user)); + if (client_init == 0) { tst = ADMCLIENTNOINIT; goto fail_afsclient_ACLEntryAdd; diff --git a/src/sys/rmtsysnet.c b/src/sys/rmtsysnet.c index bdb5c0d72a..1e6911f59a 100644 --- a/src/sys/rmtsysnet.c +++ b/src/sys/rmtsysnet.c @@ -66,7 +66,7 @@ RSkipLine(char *astr) struct Acl * RParseAcl(char *astr) { - int nplus, nminus, i, trights; + int nplus = 0, nminus = 0, i, trights = 0; char tname[MAXNAME + 1] = ""; struct AclEntry *first, *last, *tl; struct Acl *ta; @@ -75,7 +75,7 @@ RParseAcl(char *astr) sscanf(astr, "%d", &nminus); astr = RSkipLine(astr); - ta = malloc(sizeof(struct Acl)); + ta = calloc(sizeof(*ta), 1); ta->nplus = nplus; ta->nminus = nminus; @@ -84,7 +84,7 @@ RParseAcl(char *astr) for (i = 0; i < nplus; i++) { sscanf(astr, "%" opr_stringize(MAXNAME) "s %d", tname, &trights); astr = RSkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); @@ -101,7 +101,7 @@ RParseAcl(char *astr) for (i = 0; i < nminus; i++) { sscanf(astr, "%" opr_stringize(MAXNAME) "s %d", tname, &trights); astr = RSkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); diff --git a/src/uss/uss_acl.c b/src/uss/uss_acl.c index b3450ba2b2..0eb4b53bca 100644 --- a/src/uss/uss_acl.c +++ b/src/uss/uss_acl.c @@ -405,7 +405,7 @@ static struct Acl * ParseAcl(char *a_str) { /*ParseAcl */ - int nplus, nminus, i, trights; + int nplus = 0, nminus = 0, i, trights = 0; char tname[MAXNAME + 1] = ""; struct AclEntry *first, *last, *tl; struct Acl *ta; @@ -422,7 +422,7 @@ ParseAcl(char *a_str) /* * Allocate and initialize the first entry. */ - ta = malloc(sizeof(struct Acl)); + ta = calloc(sizeof(*ta), 1); ta->nplus = nplus; ta->nminus = nminus; @@ -434,7 +434,7 @@ ParseAcl(char *a_str) for (i = 0; i < nplus; i++) { sscanf(a_str, "%" opr_stringize(MAXNAME) "s %d", tname, &trights); a_str = SkipLine(a_str); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); @@ -454,7 +454,7 @@ ParseAcl(char *a_str) for (i = 0; i < nminus; i++) { sscanf(a_str, "%" opr_stringize(MAXNAME) "s %d", tname, &trights); a_str = SkipLine(a_str); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); if (!first) first = tl; strcpy(tl->name, tname); diff --git a/src/venus/fs.c b/src/venus/fs.c index 32fa73fc33..fa914a4c42 100644 --- a/src/venus/fs.c +++ b/src/venus/fs.c @@ -573,7 +573,7 @@ EmptyAcl(char *astr) struct Acl *tp; int junk; - tp = malloc(sizeof(struct Acl)); + tp = calloc(sizeof(*tp), 1); assert(tp); tp->nplus = tp->nminus = 0; tp->pluslist = tp->minuslist = 0; @@ -585,12 +585,12 @@ EmptyAcl(char *astr) static struct Acl * ParseAcl(char *astr) { - int nplus, nminus, i, trights; - char tname[MAXNAME]; + int nplus = 0, nminus = 0, i, trights = 0; + char tname[MAXNAME + 1] = ""; struct AclEntry *first, *last, *tl; struct Acl *ta; - ta = malloc(sizeof(struct Acl)); + ta = calloc(sizeof(*ta), 1); assert(ta); ta->dfs = 0; sscanf(astr, "%d dfs:%d %1024s", &ta->nplus, &ta->dfs, ta->cell); @@ -606,7 +606,7 @@ ParseAcl(char *astr) for (i = 0; i < nplus; i++) { sscanf(astr, "%99s %d", tname, &trights); astr = SkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); assert(tl); if (!first) first = tl; @@ -624,7 +624,7 @@ ParseAcl(char *astr) for (i = 0; i < nminus; i++) { sscanf(astr, "%99s %d", tname, &trights); astr = SkipLine(astr); - tl = malloc(sizeof(struct AclEntry)); + tl = calloc(sizeof(*tl), 1); assert(tl); if (!first) first = tl; -- 2.45.2