From: drh <>
Date: Fri, 12 Jun 2026 12:20:36 +0000 (+0000)
Subject: When using a read-only WAL/SHM, handle a corrupt page size in the WAL
X-Git-Tag: release~39
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=619e38a5527bf4f5db58f736e7e0cc9bd6c81f92;p=thirdparty%2Fsqlite.git

When using a read-only WAL/SHM, handle a corrupt page size in the WAL
file correctly.

FossilOrigin-Name: 9a79ca31ff2a55af0e5e8c4d2e7126355a93848ebb8c9caa0ab351202726c63d
---

diff --git a/manifest b/manifest
index 075eb1fda2..73584f4663 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\ssigned\sinteger\soverflow\sthat\scould\soccur\sin\sfts3\swhen\sprocessing\scorrupt\sdatabase\srecords.
-D 2026-06-12T11:45:37.252
+C When\susing\sa\sread-only\sWAL/SHM,\shandle\sa\scorrupt\spage\ssize\sin\sthe\sWAL\nfile\scorrectly.
+D 2026-06-12T12:20:36.203
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -814,7 +814,7 @@ F src/vdbetrace.c 49e689f751505839742f4a243a1a566e57d5c9eaf0d33bbaa26e2de3febf7b
 F src/vdbevtab.c fc46b9cbd759dc013f0b3724549cc0d71379183c667df3a5988f7e2f1bd485f3
 F src/vtab.c 5437ce986db2f70e639ce8a3fe68dcdfe64b0f1abb14eaebecdabd5e0766cc68
 F src/vxworks.h 9d18819c5235b49c2340a8a4d48195ec5d5afb637b152406de95a9436beeaeab
-F src/wal.c 7340d4f9bb827bd349127cac6b2cf0cb7f76b9fda645f7b9b0bf7a6e0b1e2e7c
+F src/wal.c abfd99239725a258af4f733681b24dd7a9ee298babe389a36d29c197e2443ebf
 F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
 F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
 F src/where.c a1caeb656f74e58de7e7310ee91c6dfb40e975c7dd9b18e61a965aea46a610f2
@@ -2200,9 +2200,9 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P a36fc58e55c100f0c26e4426100c15287dc5613e06d5d1fb43845e3c7cda09df
-Q +978d04f051c06aff798f915b0774da19a0b4f89f9daee124f7e62b12afaaced8
-R 23b774efdc8dcc6611c3d6ff9f1ae6a7
+P 42fe4d2e8bbb2ff9ebfd8a9b981bd8769f5273bba74cc1795396820f44a443cb
+Q +09ab0a1bac4eb7de651f78cfd3027b452308da7e04c4ccd7f46c402c82fd6ca5
+R b37e666026b8360c40d908cfaa4f3f3a
 U drh
-Z 8ac7bf260168a96b0a7ebe360d103e3d
+Z 5959c7b11910ea5908f58ce648506fd2
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 3d4a6d44f3..39e4f89329 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-42fe4d2e8bbb2ff9ebfd8a9b981bd8769f5273bba74cc1795396820f44a443cb
+9a79ca31ff2a55af0e5e8c4d2e7126355a93848ebb8c9caa0ab351202726c63d
diff --git a/src/wal.c b/src/wal.c
index cc8ed326cb..33fa038dba 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -1023,6 +1023,12 @@ static int walDecodeFrame(
     return 0;
   }
 
+  /* Need a valid page size
+  */
+  if( !pWal->szPage ){
+    return 0;
+  }
+
   /* A frame is only valid if a checksum of the WAL header,
   ** all prior frames, the first 16 bytes of this frame-header,
   ** and the frame-data matches the checksum in the last 8
@@ -2877,7 +2883,7 @@ static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
 
   /* Allocate a buffer to read frames into */
   assert( (pWal->szPage & (pWal->szPage-1))==0 );
-  assert( pWal->szPage>=512 && pWal->szPage<=65536 );
+  assert( (pWal->szPage>=512 && pWal->szPage<=65536) || pWal->szPage==0 );
   szFrame = pWal->szPage + WAL_FRAME_HDRSIZE;
   aFrame = (u8 *)sqlite3_malloc64(szFrame);
   if( aFrame==0 ){